llvm-6502/test/Transforms/SimplifyCFG/no_speculative_loads_with_tsan.ll
Kostya Serebryany 42a9da35b8 Don't speculate loads under ThreadSanitizer
Summary:
Don't speculate loads under ThreadSanitizer.
This fixes https://code.google.com/p/thread-sanitizer/issues/detail?id=40
Also discussed here: http://lists.cs.uiuc.edu/pipermail/llvmdev/2013-November/067929.html

Reviewers: chandlerc

Reviewed By: chandlerc

CC: llvm-commits, dvyukov

Differential Revision: http://llvm-reviews.chandlerc.com/D2227

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195324 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-21 07:29:28 +00:00

41 lines
1.2 KiB
LLVM

; RUN: opt -simplifycfg -S %s | FileCheck %s
; Make sure we don't speculate loads under ThreadSanitizer.
@g = global i32 0, align 4
define i32 @TestNoTsan(i32 %cond) nounwind readonly uwtable {
entry:
%tobool = icmp eq i32 %cond, 0
br i1 %tobool, label %return, label %if.then
if.then: ; preds = %entry
%0 = load i32* @g, align 4
br label %return
return: ; preds = %entry, %if.then
%retval = phi i32 [ %0, %if.then ], [ 0, %entry ]
ret i32 %retval
; CHECK-LABEL: @TestNoTsan
; CHECK: %[[LOAD:[^ ]*]] = load
; CHECK: select{{.*}}[[LOAD]]
; CHECK: ret i32
}
define i32 @TestTsan(i32 %cond) nounwind readonly uwtable sanitize_thread {
entry:
%tobool = icmp eq i32 %cond, 0
br i1 %tobool, label %return, label %if.then
if.then: ; preds = %entry
%0 = load i32* @g, align 4
br label %return
return: ; preds = %entry, %if.then
%retval = phi i32 [ %0, %if.then ], [ 0, %entry ]
ret i32 %retval
; CHECK-LABEL: @TestTsan
; CHECK: br i1
; CHECK: load i32* @g
; CHECK: br label
; CHECK: ret i32
}