From 66fe80aa57c6de0b48fb4efb4c7bebe35c6c28c8 Mon Sep 17 00:00:00 2001 From: Eli Friedman Date: Fri, 13 Jun 2008 21:17:49 +0000 Subject: [PATCH] Make sure SimplifyStoreAtEndOfBlock doesn't mess with loops; the structure checks are incorrect if the blocks aren't distinct. Fixes PR2435. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52257 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../Scalar/InstructionCombining.cpp | 8 +++++-- .../2008-06-13-InfiniteLoopStore.ll | 22 +++++++++++++++++++ 2 files changed, 28 insertions(+), 2 deletions(-) create mode 100644 test/Transforms/InstCombine/2008-06-13-InfiniteLoopStore.ll diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index c04df4a749b..8dbca0f2e8b 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -10379,8 +10379,12 @@ bool InstCombiner::SimplifyStoreAtEndOfBlock(StoreInst &SI) { } if (++PI != pred_end(DestBB)) return false; - - + + // Bail out if all the relevant blocks aren't distinct (this can happen, + // for example, if SI is in an infinite loop) + if (StoreBB == DestBB || OtherBB == DestBB) + return false; + // Verify that the other block ends in a branch and is not otherwise empty. BasicBlock::iterator BBI = OtherBB->getTerminator(); BranchInst *OtherBr = dyn_cast(BBI); diff --git a/test/Transforms/InstCombine/2008-06-13-InfiniteLoopStore.ll b/test/Transforms/InstCombine/2008-06-13-InfiniteLoopStore.ll new file mode 100644 index 00000000000..674042adce3 --- /dev/null +++ b/test/Transforms/InstCombine/2008-06-13-InfiniteLoopStore.ll @@ -0,0 +1,22 @@ +; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep {store i32} | count 2 +target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128" +target triple = "i386-apple-darwin8" + +@g_139 = global i32 0 ; [#uses=2] + +define void @func_56(i32 %p_60) nounwind { +entry: + store i32 1, i32* @g_139, align 4 + %tmp1 = icmp ne i32 %p_60, 0 ; [#uses=1] + %tmp12 = zext i1 %tmp1 to i8 ; [#uses=1] + %toBool = icmp ne i8 %tmp12, 0 ; [#uses=1] + br i1 %toBool, label %bb, label %return + +bb: ; preds = %bb, %entry + store i32 1, i32* @g_139, align 4 + br label %bb + +return: ; preds = %entry + ret void +} + -- 2.34.1