[llvm] r272206 - [SLPVectorizer] Handle GEP with differing constant index types

[Michael Zolotukhin via llvm-commits]

Author: mzolotukhin
Date: Wed Jun  8 16:55:16 2016
New Revision: 272206

URL: http://llvm.org/viewvc/llvm-project?rev=272206&view=rev
Log:
[SLPVectorizer] Handle GEP with differing constant index types

Summary:
This fixes PR27617.

Bug description: The SLPVectorizer asserts on encountering GEPs with different index types, such as i8 and i64.

The patch includes a simple relaxation of the assert to allow constants being of different types, along with a regression test that will provoke the unrelaxed assert.

Reviewers: nadav, mzolotukhin

Subscribers: JesperAntonsson, llvm-commits, mzolotukhin

Differential Revision: http://reviews.llvm.org/D20685

Patch by Jesper Antonsson!

Added:
    llvm/trunk/test/Transforms/SLPVectorizer/X86/gep_mismatch.ll
Modified:
    llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp

Modified: llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp?rev=272206&r1=272205&r2=272206&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp Wed Jun  8 16:55:16 2016
@@ -1014,7 +1014,7 @@ void BoUpSLP::buildTree(ArrayRef<Value *
 
 
 void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth) {
-  bool SameTy = getSameType(VL); (void)SameTy;
+  bool SameTy = allConstant(VL) || getSameType(VL); (void)SameTy;
   bool isAltShuffle = false;
   assert(SameTy && "Invalid types!");
 

Added: llvm/trunk/test/Transforms/SLPVectorizer/X86/gep_mismatch.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SLPVectorizer/X86/gep_mismatch.ll?rev=272206&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SLPVectorizer/X86/gep_mismatch.ll (added)
+++ llvm/trunk/test/Transforms/SLPVectorizer/X86/gep_mismatch.ll Wed Jun  8 16:55:16 2016
@@ -0,0 +1,22 @@
+; RUN: opt < %s -S -slp-vectorizer
+
+; This code has GEPs with different index types, which should not
+; matter for the SLPVectorizer.
+
+target triple = "x86_64--linux"
+
+define void @foo() {
+entry:
+  br label %bb1
+
+bb1:
+  %ls1.ph = phi float* [ %_tmp1, %bb1 ], [ undef, %entry ]
+  %ls2.ph = phi float* [ %_tmp2, %bb1 ], [ undef, %entry ]
+  store float undef, float* %ls1.ph
+  %_tmp1 = getelementptr float, float* %ls1.ph, i32 1
+  %_tmp2 = getelementptr float, float* %ls2.ph, i64 4
+  br i1 false, label %bb1, label %bb2
+
+bb2:
+  ret void
+}