llvm/test/Transforms/SafeStack/struct.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

41 lines
1.4 KiB
LLVM

; RUN: opt -safe-stack -S -mtriple=i386-pc-linux-gnu < %s -o - | FileCheck %s
; RUN: opt -safe-stack -S -mtriple=x86_64-pc-linux-gnu < %s -o - | FileCheck %s
%struct.foo = type { [16 x i8] }
@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
; struct { [16 x i8] }
define void @foo(i8* %a) nounwind uwtable safestack {
entry:
; CHECK: %[[USP:.*]] = load i8*, i8** @__safestack_unsafe_stack_ptr
; CHECK: %[[USST:.*]] = getelementptr i8, i8* %[[USP]], i32 -16
; CHECK: store i8* %[[USST]], i8** @__safestack_unsafe_stack_ptr
%a.addr = alloca i8*, align 8
%buf = alloca %struct.foo, align 1
; CHECK: %[[AADDR:.*]] = alloca i8*, align 8
; CHECK: store i8* {{.*}}, i8** %[[AADDR]], align 8
store i8* %a, i8** %a.addr, align 8
; CHECK: %[[BUFPTR:.*]] = getelementptr i8, i8* %[[USP]], i32 -16
; CHECK: %[[BUFPTR2:.*]] = bitcast i8* %[[BUFPTR]] to %struct.foo*
; CHECK: %[[GEP:.*]] = getelementptr inbounds %struct.foo, %struct.foo* %[[BUFPTR2]], i32 0, i32 0, i32 0
%gep = getelementptr inbounds %struct.foo, %struct.foo* %buf, i32 0, i32 0, i32 0
; CHECK: %[[A:.*]] = load i8*, i8** %[[AADDR]], align 8
%a2 = load i8*, i8** %a.addr, align 8
; CHECK: call i8* @strcpy(i8* %[[GEP]], i8* %[[A]])
%call = call i8* @strcpy(i8* %gep, i8* %a2)
; CHECK: store i8* %[[USP]], i8** @__safestack_unsafe_stack_ptr
ret void
}
declare i8* @strcpy(i8*, i8*)