From c22cdb7203e4aad8e6491487f224efff7a3e58c0 Mon Sep 17 00:00:00 2001 From: Derek Schuff Date: Wed, 15 May 2013 21:15:09 +0000 Subject: Fix miscompile due to StackColoring incorrectly merging stack slots (PR15707) IR optimisation passes can result in a basic block that contains: llvm.lifetime.start(%buf) ... llvm.lifetime.end(%buf) ... llvm.lifetime.start(%buf) Before this change, calculateLiveIntervals() was ignoring the second lifetime.start() and was regarding %buf as being dead from the lifetime.end() through to the end of the basic block. This can cause StackColoring to incorrectly merge %buf with another stack slot. Fix by removing the incorrect Starts[pos].isValid() and Finishes[pos].isValid() checks. Just doing: Starts[pos] = Indexes->getMBBStartIdx(MBB); Finishes[pos] = Indexes->getMBBEndIdx(MBB); unconditionally would be enough to fix the bug, but it causes some test failures due to stack slots not being merged when they were before. So, in order to keep the existing tests passing, treat LiveIn and LiveOut separately rather than approximating the live ranges by merging LiveIn and LiveOut. This fixes PR15707. Patch by Mark Seaborn. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181922 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/CodeGen/X86/StackColoring.ll | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'test') diff --git a/test/CodeGen/X86/StackColoring.ll b/test/CodeGen/X86/StackColoring.ll index f8ae74f292..6c0f00d17d 100644 --- a/test/CodeGen/X86/StackColoring.ll +++ b/test/CodeGen/X86/StackColoring.ll @@ -350,6 +350,28 @@ bb3: ret i32 0 } + +; Regression test for PR15707. %buf1 and %buf2 should not be merged +; in this test case. +;YESCOLOR: myCall_pr15707 +;YESCOLOR: subq $200008, %rsp +;NOCOLOR: myCall_pr15707 +;NOCOLOR: subq $200008, %rsp +define void @myCall_pr15707() { + %buf1 = alloca i8, i32 100000, align 16 + %buf2 = alloca i8, i32 100000, align 16 + + call void @llvm.lifetime.start(i64 -1, i8* %buf1) + call void @llvm.lifetime.end(i64 -1, i8* %buf1) + + call void @llvm.lifetime.start(i64 -1, i8* %buf1) + call void @llvm.lifetime.start(i64 -1, i8* %buf2) + %result1 = call i32 @foo(i32 0, i8* %buf1) + %result2 = call i32 @foo(i32 0, i8* %buf2) + ret void +} + + ; Check that we don't assert and crash even when there are allocas ; outside the declared lifetime regions. ;YESCOLOR: bad_range -- cgit v1.2.3