llvm/test/Transforms/SafeStack/sink-to-use.ll
Evgeniy Stepanov f268616d77 [safestack] Sink unsafe address computation to each use.
This is a fix for PR27844.
When replacing uses of unsafe allocas, emit the new location
immediately after each use. Without this, the pointer stays live from
the function entry to the last use, while it's usually cheaper to
recalculate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272969 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-16 22:34:04 +00:00

23 lines
720 B
LLVM

; Test that unsafe alloca address calculation is done immediately before each use.
; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
define void @f() safestack {
entry:
%x0 = alloca i32, align 4
%x1 = alloca i32, align 4
; CHECK: %[[A:.*]] = getelementptr i8, i8* %{{.*}}, i32 -4
; CHECK: %[[X0:.*]] = bitcast i8* %[[A]] to i32*
; CHECK: call void @use(i32* %[[X0]])
call void @use(i32* %x0)
; CHECK: %[[B:.*]] = getelementptr i8, i8* %{{.*}}, i32 -8
; CHECK: %[[X1:.*]] = bitcast i8* %[[B]] to i32*
; CHECK: call void @use(i32* %[[X1]])
call void @use(i32* %x1)
ret void
}
declare void @use(i32*)