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llvm-mirror/test/CodeGen/WinEH/wineh-statenumbering.ll

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[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
; RUN: opt -mtriple=i686-pc-windows-msvc -S -x86-winehstate < %s | FileCheck %s
target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
target triple = "i686-pc-windows-msvc"
%rtti.TypeDescriptor2 = type { i8**, i8*, [3 x i8] }
%eh.CatchableType = type { i32, i8*, i32, i32, i32, i32, i8* }
%eh.CatchableTypeArray.1 = type { i32, [1 x %eh.CatchableType*] }
%eh.ThrowInfo = type { i32, i8*, i8*, i8* }
$"\01??_R0H@8" = comdat any
$"_CT??_R0H@84" = comdat any
$_CTA1H = comdat any
$_TI1H = comdat any
@"\01??_7type_info@@6B@" = external constant i8*
@"\01??_R0H@8" = linkonce_odr global %rtti.TypeDescriptor2 { i8** @"\01??_7type_info@@6B@", i8* null, [3 x i8] c".H\00" }, comdat
@"_CT??_R0H@84" = linkonce_odr unnamed_addr constant %eh.CatchableType { i32 1, i8* bitcast (%rtti.TypeDescriptor2* @"\01??_R0H@8" to i8*), i32 0, i32 -1, i32 0, i32 4, i8* null }, section ".xdata", comdat
@_CTA1H = linkonce_odr unnamed_addr constant %eh.CatchableTypeArray.1 { i32 1, [1 x %eh.CatchableType*] [%eh.CatchableType* @"_CT??_R0H@84"] }, section ".xdata", comdat
@_TI1H = linkonce_odr unnamed_addr constant %eh.ThrowInfo { i32 0, i8* null, i8* null, i8* bitcast (%eh.CatchableTypeArray.1* @_CTA1H to i8*) }, section ".xdata", comdat
define i32 @main() #0 personality i32 (...)* @__CxxFrameHandler3 {
entry:
%tmp = alloca i32, align 4
; CHECK: entry:
; CHECK: store i32 -1
; CHECK: call void @g(i32 3)
[WinEH] Optimize WinEH state stores 32-bit x86 Windows targets use a linked-list of nodes allocated on the stack, referenced to via thread-local storage. The personality routine interprets one of the fields in the node as a 'state number' which indicates where the personality routine should transfer control. State transitions are possible only before call-sites which may throw exceptions. Our previous scheme had us update the state number before all call-sites which may throw. Instead, we can try to minimize the number of times we need to store by reasoning about the nearest store which dominates the current call-site. If the last store agrees with the current call-site, then we know that the state-update is redundant and can be elided. This is largely straightforward: an RPO walk of the blocks allows us to correctly forward propagate the information when the function is a DAG. Currently, loops are not handled optimally and may trigger superfluous state stores. Differential Revision: http://reviews.llvm.org/D16763 llvm-svn: 261122
2016-02-17 19:37:11 +01:00
; CHECK-NEXT: call void @g(i32 4)
; CHECK-NEXT: call void @g(i32 5)
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
call void @g(i32 3)
[WinEH] Optimize WinEH state stores 32-bit x86 Windows targets use a linked-list of nodes allocated on the stack, referenced to via thread-local storage. The personality routine interprets one of the fields in the node as a 'state number' which indicates where the personality routine should transfer control. State transitions are possible only before call-sites which may throw exceptions. Our previous scheme had us update the state number before all call-sites which may throw. Instead, we can try to minimize the number of times we need to store by reasoning about the nearest store which dominates the current call-site. If the last store agrees with the current call-site, then we know that the state-update is redundant and can be elided. This is largely straightforward: an RPO walk of the blocks allows us to correctly forward propagate the information when the function is a DAG. Currently, loops are not handled optimally and may trigger superfluous state stores. Differential Revision: http://reviews.llvm.org/D16763 llvm-svn: 261122
2016-02-17 19:37:11 +01:00
call void @g(i32 4)
call void @g(i32 5)
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
store i32 0, i32* %tmp, align 4
%0 = bitcast i32* %tmp to i8*
; CHECK: store i32 0
; CHECK: invoke void @_CxxThrowException(
invoke void @_CxxThrowException(i8* %0, %eh.ThrowInfo* nonnull @_TI1H) #1
to label %unreachable.for.entry unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 06:38:55 +01:00
%cs1 = catchswitch within none [label %catch] unwind to caller
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
catch: ; preds = %catch.dispatch
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 06:38:55 +01:00
%1 = catchpad within %cs1 [i8* null, i32 u0x40, i8* null]
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
; CHECK: catch:
; CHECK: store i32 2
; CHECK: invoke void @_CxxThrowException(
[WinEH] Verify consistent funclet unwind exits Summary: A funclet EH pad may be exited by an unwind edge, which may be a cleanupret exiting its cleanuppad, an invoke exiting a funclet, or an unwind out of a nested funclet transitively exiting its parent. Funclet EH personalities require all such exceptional exits from a given funclet to have the same unwind destination, and EH preparation / state numbering / table generation implicitly depends on this. Formalize it as a rule of the IR in the LangRef and verifier. Reviewers: rnk, majnemer, andrew.w.kaylor Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D15962 llvm-svn: 257273
2016-01-10 05:30:02 +01:00
invoke void @_CxxThrowException(i8* null, %eh.ThrowInfo* null) [ "funclet"(token %1) ]
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
to label %unreachable unwind label %catch.dispatch.1
catch.dispatch.1: ; preds = %catch
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 06:38:55 +01:00
%cs2 = catchswitch within %1 [label %catch.3] unwind to caller
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
catch.3: ; preds = %catch.dispatch.1
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 06:38:55 +01:00
%2 = catchpad within %cs2 [i8* null, i32 u0x40, i8* null]
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
; CHECK: catch.3:
; CHECK: store i32 3
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 06:38:55 +01:00
; CHECK: call void @g(i32 1)
[WinEH] Optimize WinEH state stores 32-bit x86 Windows targets use a linked-list of nodes allocated on the stack, referenced to via thread-local storage. The personality routine interprets one of the fields in the node as a 'state number' which indicates where the personality routine should transfer control. State transitions are possible only before call-sites which may throw exceptions. Our previous scheme had us update the state number before all call-sites which may throw. Instead, we can try to minimize the number of times we need to store by reasoning about the nearest store which dominates the current call-site. If the last store agrees with the current call-site, then we know that the state-update is redundant and can be elided. This is largely straightforward: an RPO walk of the blocks allows us to correctly forward propagate the information when the function is a DAG. Currently, loops are not handled optimally and may trigger superfluous state stores. Differential Revision: http://reviews.llvm.org/D16763 llvm-svn: 261122
2016-02-17 19:37:11 +01:00
; CHECK-NEXT: call void @g(i32 2)
; CHECK-NEXT: call void @g(i32 3)
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 06:38:55 +01:00
call void @g(i32 1)
[WinEH] Optimize WinEH state stores 32-bit x86 Windows targets use a linked-list of nodes allocated on the stack, referenced to via thread-local storage. The personality routine interprets one of the fields in the node as a 'state number' which indicates where the personality routine should transfer control. State transitions are possible only before call-sites which may throw exceptions. Our previous scheme had us update the state number before all call-sites which may throw. Instead, we can try to minimize the number of times we need to store by reasoning about the nearest store which dominates the current call-site. If the last store agrees with the current call-site, then we know that the state-update is redundant and can be elided. This is largely straightforward: an RPO walk of the blocks allows us to correctly forward propagate the information when the function is a DAG. Currently, loops are not handled optimally and may trigger superfluous state stores. Differential Revision: http://reviews.llvm.org/D16763 llvm-svn: 261122
2016-02-17 19:37:11 +01:00
call void @g(i32 2)
call void @g(i32 3)
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 06:38:55 +01:00
catchret from %2 to label %try.cont
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 06:38:55 +01:00
try.cont: ; preds = %catch.3
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
; CHECK: try.cont:
; CHECK: store i32 1
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 06:38:55 +01:00
; CHECK: call void @g(i32 2)
[WinEH] Optimize WinEH state stores 32-bit x86 Windows targets use a linked-list of nodes allocated on the stack, referenced to via thread-local storage. The personality routine interprets one of the fields in the node as a 'state number' which indicates where the personality routine should transfer control. State transitions are possible only before call-sites which may throw exceptions. Our previous scheme had us update the state number before all call-sites which may throw. Instead, we can try to minimize the number of times we need to store by reasoning about the nearest store which dominates the current call-site. If the last store agrees with the current call-site, then we know that the state-update is redundant and can be elided. This is largely straightforward: an RPO walk of the blocks allows us to correctly forward propagate the information when the function is a DAG. Currently, loops are not handled optimally and may trigger superfluous state stores. Differential Revision: http://reviews.llvm.org/D16763 llvm-svn: 261122
2016-02-17 19:37:11 +01:00
; CHECK-NEXT: call void @g(i32 3)
; CHECK-NEXT: call void @g(i32 4)
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 06:38:55 +01:00
call void @g(i32 2)
[WinEH] Optimize WinEH state stores 32-bit x86 Windows targets use a linked-list of nodes allocated on the stack, referenced to via thread-local storage. The personality routine interprets one of the fields in the node as a 'state number' which indicates where the personality routine should transfer control. State transitions are possible only before call-sites which may throw exceptions. Our previous scheme had us update the state number before all call-sites which may throw. Instead, we can try to minimize the number of times we need to store by reasoning about the nearest store which dominates the current call-site. If the last store agrees with the current call-site, then we know that the state-update is redundant and can be elided. This is largely straightforward: an RPO walk of the blocks allows us to correctly forward propagate the information when the function is a DAG. Currently, loops are not handled optimally and may trigger superfluous state stores. Differential Revision: http://reviews.llvm.org/D16763 llvm-svn: 261122
2016-02-17 19:37:11 +01:00
call void @g(i32 3)
call void @g(i32 4)
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
unreachable
unreachable: ; preds = %catch
unreachable
unreachable.for.entry: ; preds = %entry
unreachable
}
[WinEH] Skip state numbering when no EH pads are present Otherwise we'd try to emit the thunk that passes the LSDA to __CxxFrameHandler3. We don't emit the LSDA if there were no landingpads, so we'd end up with an assembler error when trying to write the COFF object. llvm-svn: 247820
2015-09-16 19:19:44 +02:00
define i32 @nopads() #0 personality i32 (...)* @__CxxFrameHandler3 {
ret i32 0
}
; CHECK-LABEL: define i32 @nopads()
; CHECK-NEXT: ret i32 0
; CHECK-NOT: __ehhandler$nopads
[WinEH] Don't visit the same catchswitch twice We visited the same catchswitch twice because it was both the child of another funclet and the predecessor of a cleanuppad. Instead, change the numbering algorithm to only recurse if the unwind destination of the inner funclet agrees with the unwind destination of the catchswitch. This fixes PR25926. llvm-svn: 256317
2015-12-23 04:59:04 +01:00
; CHECK-LABEL: define void @PR25926()
define void @PR25926() personality i32 (...)* @__CxxFrameHandler3 {
entry:
; CHECK: entry:
; CHECK: store i32 -1
; CHECK: store i32 0
; CHECK: invoke void @_CxxThrowException(
invoke void @_CxxThrowException(i8* null, %eh.ThrowInfo* null)
to label %unreachable unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchswitch within none [label %catch] unwind to caller
catch: ; preds = %catch.dispatch
%1 = catchpad within %0 [i8* null, i32 64, i8* null]
; CHECK: catch:
; CHECK: store i32 3
; CHECK: invoke void @_CxxThrowException(
invoke void @_CxxThrowException(i8* null, %eh.ThrowInfo* null) [ "funclet"(token %1) ]
to label %unreachable1 unwind label %catch.dispatch1
catch.dispatch1: ; preds = %catch
%2 = catchswitch within %1 [label %catch2] unwind label %ehcleanup
catch2: ; preds = %catch.dispatch1
%3 = catchpad within %2 [i8* null, i32 64, i8* null]
catchret from %3 to label %try.cont
try.cont: ; preds = %catch2
; CHECK: try.cont:
; CHECK: store i32 1
; CHECK: call void @dtor()
[WinEH] Optimize WinEH state stores 32-bit x86 Windows targets use a linked-list of nodes allocated on the stack, referenced to via thread-local storage. The personality routine interprets one of the fields in the node as a 'state number' which indicates where the personality routine should transfer control. State transitions are possible only before call-sites which may throw exceptions. Our previous scheme had us update the state number before all call-sites which may throw. Instead, we can try to minimize the number of times we need to store by reasoning about the nearest store which dominates the current call-site. If the last store agrees with the current call-site, then we know that the state-update is redundant and can be elided. This is largely straightforward: an RPO walk of the blocks allows us to correctly forward propagate the information when the function is a DAG. Currently, loops are not handled optimally and may trigger superfluous state stores. Differential Revision: http://reviews.llvm.org/D16763 llvm-svn: 261122
2016-02-17 19:37:11 +01:00
; CHECK-NEXT: call void @dtor()
; CHECK-NEXT: call void @dtor()
call void @dtor() #3 [ "funclet"(token %1) ]
call void @dtor() #3 [ "funclet"(token %1) ]
[WinEH] Don't visit the same catchswitch twice We visited the same catchswitch twice because it was both the child of another funclet and the predecessor of a cleanuppad. Instead, change the numbering algorithm to only recurse if the unwind destination of the inner funclet agrees with the unwind destination of the catchswitch. This fixes PR25926. llvm-svn: 256317
2015-12-23 04:59:04 +01:00
call void @dtor() #3 [ "funclet"(token %1) ]
catchret from %1 to label %try.cont4
try.cont4: ; preds = %try.cont
ret void
ehcleanup: ; preds = %catch.dispatch1
%4 = cleanuppad within %1 []
; CHECK: ehcleanup:
; CHECK: call void @dtor()
call void @dtor() #3 [ "funclet"(token %4) ]
cleanupret from %4 unwind to caller
unreachable: ; preds = %entry
unreachable
unreachable1: ; preds = %catch
unreachable
}
[WinEH] Optimize WinEH state stores 32-bit x86 Windows targets use a linked-list of nodes allocated on the stack, referenced to via thread-local storage. The personality routine interprets one of the fields in the node as a 'state number' which indicates where the personality routine should transfer control. State transitions are possible only before call-sites which may throw exceptions. Our previous scheme had us update the state number before all call-sites which may throw. Instead, we can try to minimize the number of times we need to store by reasoning about the nearest store which dominates the current call-site. If the last store agrees with the current call-site, then we know that the state-update is redundant and can be elided. This is largely straightforward: an RPO walk of the blocks allows us to correctly forward propagate the information when the function is a DAG. Currently, loops are not handled optimally and may trigger superfluous state stores. Differential Revision: http://reviews.llvm.org/D16763 llvm-svn: 261122
2016-02-17 19:37:11 +01:00
; CHECK-LABEL: define void @required_state_store(
define void @required_state_store(i1 zeroext %cond) personality i32 (...)* @_except_handler3 {
entry:
%__exception_code = alloca i32, align 4
call void (...) @llvm.localescape(i32* nonnull %__exception_code)
; CHECK: store i32 -1
; CHECK: call void @g(i32 0)
call void @g(i32 0)
br i1 %cond, label %if.then, label %if.end
if.then: ; preds = %entry
; CHECK: store i32 0
; CHECK-NEXT: invoke void @g(i32 1)
invoke void @g(i32 1)
to label %if.end unwind label %catch.dispatch
catch.dispatch: ; preds = %if.then
%0 = catchswitch within none [label %__except.ret] unwind to caller
__except.ret: ; preds = %catch.dispatch
%1 = catchpad within %0 [i8* bitcast (i32 ()* @"\01?filt$0@0@required_state_store@@" to i8*)]
catchret from %1 to label %if.end
if.end: ; preds = %if.then, %__except.ret, %entry
; CHECK: store i32 -1
; CHECK-NEXT: call void @dtor()
call void @dtor()
ret void
}
define internal i32 @"\01?filt$0@0@required_state_store@@"() {
entry:
%0 = tail call i8* @llvm.frameaddress(i32 1)
%1 = tail call i8* @llvm.x86.seh.recoverfp(i8* bitcast (void (i1)* @required_state_store to i8*), i8* %0)
%2 = tail call i8* @llvm.localrecover(i8* bitcast (void (i1)* @required_state_store to i8*), i8* %1, i32 0)
%__exception_code = bitcast i8* %2 to i32*
%3 = getelementptr inbounds i8, i8* %0, i32 -20
%4 = bitcast i8* %3 to { i32*, i8* }**
%5 = load { i32*, i8* }*, { i32*, i8* }** %4, align 4
%6 = getelementptr inbounds { i32*, i8* }, { i32*, i8* }* %5, i32 0, i32 0
%7 = load i32*, i32** %6, align 4
%8 = load i32, i32* %7, align 4
store i32 %8, i32* %__exception_code, align 4
ret i32 1
}
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
declare void @g(i32) #0
[WinEH] Don't visit the same catchswitch twice We visited the same catchswitch twice because it was both the child of another funclet and the predecessor of a cleanuppad. Instead, change the numbering algorithm to only recurse if the unwind destination of the inner funclet agrees with the unwind destination of the catchswitch. This fixes PR25926. llvm-svn: 256317
2015-12-23 04:59:04 +01:00
declare void @dtor()
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
declare x86_stdcallcc void @_CxxThrowException(i8*, %eh.ThrowInfo*)
declare i32 @__CxxFrameHandler3(...)
[WinEH] Optimize WinEH state stores 32-bit x86 Windows targets use a linked-list of nodes allocated on the stack, referenced to via thread-local storage. The personality routine interprets one of the fields in the node as a 'state number' which indicates where the personality routine should transfer control. State transitions are possible only before call-sites which may throw exceptions. Our previous scheme had us update the state number before all call-sites which may throw. Instead, we can try to minimize the number of times we need to store by reasoning about the nearest store which dominates the current call-site. If the last store agrees with the current call-site, then we know that the state-update is redundant and can be elided. This is largely straightforward: an RPO walk of the blocks allows us to correctly forward propagate the information when the function is a DAG. Currently, loops are not handled optimally and may trigger superfluous state stores. Differential Revision: http://reviews.llvm.org/D16763 llvm-svn: 261122
2016-02-17 19:37:11 +01:00
declare i8* @llvm.frameaddress(i32)
declare i8* @llvm.x86.seh.recoverfp(i8*, i8*)
declare i8* @llvm.localrecover(i8*, i8*, i32)
declare void @llvm.localescape(...)
declare i32 @_except_handler3(...)
[WinEH] Calculate state numbers for the new EH representation State numbers are calculated by performing a walk from the innermost funclet to the outermost funclet. Rudimentary support for the new EH constructs has been added to the assembly printer, just enough to test the new machinery. Differential Revision: http://reviews.llvm.org/D12098 llvm-svn: 245331
2015-08-18 21:07:12 +02:00
attributes #0 = { "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { noreturn }
!llvm.ident = !{!0}
!0 = !{!"clang version 3.8.0 (trunk 245153) (llvm/trunk 245238)"}
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