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llvm-mirror/test/Transforms/SafeStack/cast.ll
Evgeniy Stepanov cabb944249 [safestack] Rewrite isAllocaSafe using SCEV.
Use ScalarEvolution to calculate memory access bounds.
Handle function calls based on readnone/nocapture attributes.
Handle memory intrinsics with constant size.

This change improves both recall and precision of IsAllocaSafe.
See the new tests (ex. BitCastWide) for the kind of code that was wrongly
classified as safe.

SCEV efficiency seems to be limited by the fact the SafeStack runs late
(in CodeGenPrepare), and many loops are unrolled or otherwise not in LCSSA.

llvm-svn: 253083
2015-11-13 21:21:42 +00:00

40 lines
1.0 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
@.str = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
; PtrToInt/IntToPtr Cast
define void @IntToPtr() nounwind uwtable safestack {
entry:
; CHECK-LABEL: @IntToPtr(
; CHECK-NOT: __safestack_unsafe_stack_ptr
; CHECK: ret void
%a = alloca i32, align 4
%0 = ptrtoint i32* %a to i64
%1 = inttoptr i64 %0 to i32*
ret void
}
define i8 @BitCastNarrow() nounwind uwtable safestack {
entry:
; CHECK-LABEL: @BitCastNarrow(
; CHECK-NOT: __safestack_unsafe_stack_ptr
; CHECK: ret i8
%a = alloca i32, align 4
%0 = bitcast i32* %a to i8*
%1 = load i8, i8* %0, align 1
ret i8 %1
}
define i64 @BitCastWide() nounwind uwtable safestack {
entry:
; CHECK-LABEL: @BitCastWide(
; CHECK: __safestack_unsafe_stack_ptr
; CHECK: ret i64
%a = alloca i32, align 4
%0 = bitcast i32* %a to i64*
%1 = load i64, i64* %0, align 1
ret i64 %1
}