From bc69dc1d880792c0c2bbea189c3dbb2c39505391 Mon Sep 17 00:00:00 2001 From: Pawel Wodnicki Date: Mon, 26 Nov 2012 16:52:27 +0000 Subject: Merging r168196: into the 3.2 release branch. Make this easier to understand, as suggested by Chandler. git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_32@168594 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/InstructionSimplify.cpp | 7 ++++++- lib/Transforms/InstCombine/InstCombineCompares.cpp | 7 ++++++- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index c24c18f807..a76e5ad1b8 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -2067,15 +2067,20 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, // Determine Y and Z in the form icmp (X+Y), (X+Z). Value *Y, *Z; if (A == C) { + // C + B == C + D -> B == D Y = B; Z = D; } else if (A == D) { + // D + B == C + D -> B == C Y = B; Z = C; } else if (B == C) { + // A + C == C + D -> A == D Y = A; Z = D; - } else if (B == D) { + } else { + assert(B == D); + // A + D == C + D -> A == C Y = A; Z = C; } diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index e223a049f0..7c3f8fe15d 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -2358,15 +2358,20 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // Determine Y and Z in the form icmp (X+Y), (X+Z). Value *Y, *Z; if (A == C) { + // C + B == C + D -> B == D Y = B; Z = D; } else if (A == D) { + // D + B == C + D -> B == C Y = B; Z = C; } else if (B == C) { + // A + C == C + D -> A == D Y = A; Z = D; - } else if (B == D) { + } else { + assert(B == D); + // A + D == C + D -> A == C Y = A; Z = C; } -- cgit v1.2.3