mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-24 03:33:20 +01:00
93a823bc7a
This was motivated by a bug which caused code like this to be
miscompiled:
declare void @take_ptr(i8*)
define void @test() {
%addr1.32 = alloca i8
%addr2.32 = alloca i32, i32 1028
call void @take_ptr(i8* %addr1)
ret void
}
This was emitting the following assembly to get the value of %addr1:
add r0, sp, #1020
add r0, r0, #8
However, "add r0, r0, #8" is not a valid Thumb1 instruction, and this
could not be assembled. The generated object file contained this,
resulting in r0 holding SP+8 rather tha SP+1028:
add r0, sp, #1020
add r0, sp, #8
This function looked like it could have caused miscompilations for
other combinations of registers and offsets (though I don't think it is
currently called with these), and the heuristic it used did not match
the emitted code in all cases.
llvm-svn: 222125
81 lines
2.2 KiB
LLVM
81 lines
2.2 KiB
LLVM
; RUN: llc < %s -mtriple=thumb-apple-ios | FileCheck %s --check-prefix=CHECK --check-prefix=IOS
|
|
; RUN: llc < %s -mtriple=thumb-none-eabi | FileCheck %s --check-prefix=CHECK --check-prefix=EABI
|
|
; RUN: llc < %s -o %t -filetype=obj -mtriple=thumbv6-apple-ios
|
|
; RUN: llvm-objdump -triple=thumbv6-apple-ios -d %t | FileCheck %s --check-prefix=CHECK --check-prefix=IOS
|
|
; RUN: llc < %s -o %t -filetype=obj -mtriple=thumbv6-none-eabi
|
|
; RUN: llvm-objdump -triple=thumbv6-none-eabi -d %t | FileCheck %s --check-prefix=CHECK --check-prefix=EABI
|
|
|
|
; Largest stack for which a single tADDspi/tSUBspi is enough
|
|
define void @test1() {
|
|
; CHECK-LABEL: test1:
|
|
; CHECK: sub sp, #508
|
|
; CHECK: add sp, #508
|
|
%tmp = alloca [ 508 x i8 ] , align 4
|
|
ret void
|
|
}
|
|
|
|
; Largest stack for which three tADDspi/tSUBspis are enough
|
|
define void @test100() {
|
|
; CHECK-LABEL: test100:
|
|
; CHECK: sub sp, #508
|
|
; CHECK: sub sp, #508
|
|
; CHECK: sub sp, #508
|
|
; EABI: add sp, #508
|
|
; EABI: add sp, #508
|
|
; EABI: add sp, #508
|
|
; IOS: subs r4, r7, #4
|
|
; IOS: mov sp, r4
|
|
%tmp = alloca [ 1524 x i8 ] , align 4
|
|
ret void
|
|
}
|
|
|
|
; Smallest stack for which we use a constant pool
|
|
define void @test2() {
|
|
; CHECK-LABEL: test2:
|
|
; CHECK: ldr r0,
|
|
; CHECK: add sp, r0
|
|
; EABI: ldr r0,
|
|
; EABI: add sp, r0
|
|
; IOS: subs r4, r7, #4
|
|
; IOS: mov sp, r4
|
|
%tmp = alloca [ 1528 x i8 ] , align 4
|
|
ret void
|
|
}
|
|
|
|
define i32 @test3() {
|
|
; CHECK-LABEL: test3:
|
|
; CHECK: ldr r1,
|
|
; CHECK: add sp, r1
|
|
; CHECK: ldr r1,
|
|
; CHECK: add r1, sp
|
|
; EABI: ldr r1,
|
|
; EABI: add sp, r1
|
|
; IOS: subs r4, r7, #4
|
|
; IOS: mov sp, r4
|
|
%retval = alloca i32, align 4
|
|
%tmp = alloca i32, align 4
|
|
%a = alloca [805306369 x i8], align 16
|
|
store i32 0, i32* %tmp
|
|
%tmp1 = load i32* %tmp
|
|
ret i32 %tmp1
|
|
}
|
|
|
|
; Here, the adds get optimized out because they are dead, but the calculation
|
|
; of the address of stack_a is dead but not optimized out. When the address
|
|
; calculation gets expanded to two instructions, we need to avoid reading a
|
|
; dead register.
|
|
; No CHECK lines (just test for crashes), as we hope this will be optimised
|
|
; better in future.
|
|
define i32 @test4() {
|
|
entry:
|
|
%stack_a = alloca i8, align 1
|
|
%stack_b = alloca [256 x i32*], align 4
|
|
%int = ptrtoint i8* %stack_a to i32
|
|
%add = add i32 %int, 1
|
|
br label %block2
|
|
|
|
block2:
|
|
%add2 = add i32 %add, 1
|
|
ret i32 0
|
|
}
|