mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-25 12:12:47 +01:00
99ca015392
Teach LLVM optimize to more precisely in the presence of "deopt" operand bundles. "deopt" operand bundles imply that the call they're attached to is at least `readonly` (i.e. they don't imply clobber semantics), and they don't capture their bundle operands. llvm-svn: 254118
52 lines
1.7 KiB
LLVM
52 lines
1.7 KiB
LLVM
; RUN: opt -S -basicaa -gvn < %s | FileCheck %s
|
|
|
|
declare void @argmemonly_function(i32 *) argmemonly
|
|
|
|
define i32 @test0(i32* %P, i32* noalias %P2) {
|
|
; CHECK-LABEL: @test0(
|
|
%v1 = load i32, i32* %P
|
|
; CHECK: %v1 = load i32, i32* %P
|
|
call void @argmemonly_function(i32* %P2) [ "tag"() ]
|
|
; CHECK: call void @argmemonly_function(
|
|
%v2 = load i32, i32* %P
|
|
; CHECK: %v2 = load i32, i32* %P
|
|
%diff = sub i32 %v1, %v2
|
|
; CHECK: %diff = sub i32 %v1, %v2
|
|
ret i32 %diff
|
|
; CHECK: ret i32 %diff
|
|
}
|
|
|
|
define i32 @test1(i32* %P, i32* noalias %P2) {
|
|
; CHECK-LABEL: @test1(
|
|
%v1 = load i32, i32* %P
|
|
call void @argmemonly_function(i32* %P2) argmemonly [ "tag"() ]
|
|
; CHECK: call void @argmemonly_function(
|
|
%v2 = load i32, i32* %P
|
|
%diff = sub i32 %v1, %v2
|
|
ret i32 %diff
|
|
; CHECK: ret i32 0
|
|
}
|
|
|
|
define i32 @test2(i32* %P, i32* noalias %P2) {
|
|
; Note: in this test we //can// GVN %v1 and %v2 into one value in theory. Calls
|
|
; with deopt operand bundles are not argmemonly because they *read* the entire
|
|
; heap, but they don't write to any location in the heap if the callee does not
|
|
; deoptimize the caller. This fact, combined with the fact that
|
|
; @argmemonly_function is, well, an argmemonly function, can be used to conclude
|
|
; that %P is not written to at the callsite. However LLVM currently cannot
|
|
; describe the "does not write to non-args, and reads the entire heap" effect on
|
|
; a callsite.
|
|
|
|
; CHECK-LABEL: @test2(
|
|
%v1 = load i32, i32* %P
|
|
; CHECK: %v1 = load i32, i32* %P
|
|
call void @argmemonly_function(i32* %P2) [ "deopt"() ]
|
|
; CHECK: call void @argmemonly_function(
|
|
%v2 = load i32, i32* %P
|
|
; CHECK: %v2 = load i32, i32* %P
|
|
%diff = sub i32 %v1, %v2
|
|
; CHECK: %diff = sub i32 %v1, %v2
|
|
ret i32 %diff
|
|
; CHECK: ret i32 %diff
|
|
}
|