llvm-6502/test/Instrumentation/AddressSanitizer/lifetime-uar.ll
Anna Zaks f891336a25 [asan] Skip promotable allocas to improve performance at -O0
Currently, the ASan executables built with -O0 are unnecessarily slow.
The main reason is that ASan instrumentation pass inserts redundant
checks around promotable allocas. These allocas do not get instrumented
under -O1 because they get converted to virtual registered by mem2reg.
With this patch, ASan instrumentation pass will only instrument non
promotable allocas, giving us a speedup of 39% on a collection of
benchmarks with -O0. (There is no measurable speedup at -O1.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230724 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 03:12:36 +00:00

34 lines
1.1 KiB
LLVM

; Test handling of llvm.lifetime intrinsics in UAR mode.
; RUN: opt < %s -asan -asan-module -asan-use-after-return -asan-check-lifetime -S | FileCheck %s
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
declare void @llvm.lifetime.start(i64, i8* nocapture) nounwind
declare void @llvm.lifetime.end(i64, i8* nocapture) nounwind
define i32 @basic_test() sanitize_address {
; CHECK-LABEL: define i32 @basic_test()
entry:
%retval = alloca i32, align 4
%c = alloca i8, align 1
call void @llvm.lifetime.start(i64 1, i8* %c)
; Memory is unpoisoned at llvm.lifetime.start
; CHECK: call void @__asan_unpoison_stack_memory(i64 %{{[^ ]+}}, i64 1)
store volatile i32 0, i32* %retval
store volatile i8 0, i8* %c, align 1
call void @llvm.lifetime.end(i64 1, i8* %c)
; Memory is poisoned at llvm.lifetime.end
; CHECK: call void @__asan_poison_stack_memory(i64 %{{[^ ]+}}, i64 1)
; No need to unpoison memory at function exit in UAR mode.
; CHECK-NOT: @__asan_unpoison_stack_memory
; CHECK: ret void
ret i32 0
}