[llvm] r291692 - [SLP] Remove bogus assert.

[Michael Kuperstein via llvm-commits]

Author: mkuper
Date: Wed Jan 11 13:23:57 2017
New Revision: 291692

URL: http://llvm.org/viewvc/llvm-project?rev=291692&view=rev
Log:
[SLP] Remove bogus assert.

The removed assert seems bogus - it's perfectly legal for the roots of the
vectorized subtrees to be equal even if the original scalar values aren't,
if the original scalars happen to be equivalent.

This fixes PR31599.

Differential Revision: https://reviews.llvm.org/D28539

Added:
    llvm/trunk/test/Transforms/SLPVectorizer/X86/pr31599.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=291692&r1=291691&r2=291692&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp Wed Jan 11 13:23:57 2017
@@ -2493,10 +2493,6 @@ Value *BoUpSLP::vectorizeTree(TreeEntry
       Value *LHS = vectorizeTree(LHSVL);
       Value *RHS = vectorizeTree(RHSVL);
 
-      if (LHS == RHS && isa<Instruction>(LHS)) {
-        assert((VL0->getOperand(0) == VL0->getOperand(1)) && "Invalid order");
-      }
-
       if (Value *V = alreadyVectorized(E->Scalars))
         return V;
 

Added: llvm/trunk/test/Transforms/SLPVectorizer/X86/pr31599.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SLPVectorizer/X86/pr31599.ll?rev=291692&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SLPVectorizer/X86/pr31599.ll (added)
+++ llvm/trunk/test/Transforms/SLPVectorizer/X86/pr31599.ll Wed Jan 11 13:23:57 2017
@@ -0,0 +1,30 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -slp-vectorizer -S -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s
+
+define <2 x float> @foo() {
+; CHECK-LABEL: @foo(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[SOURCE:%.*]] = insertelement <2 x float> undef, float undef, i32 0
+; CHECK-NEXT:    [[TMP0:%.*]] = fsub <2 x float> [[SOURCE]], [[SOURCE]]
+; CHECK-NEXT:    [[TMP1:%.*]] = extractelement <2 x float> [[TMP0]], i32 0
+; CHECK-NEXT:    [[RES1:%.*]] = insertelement <2 x float> undef, float [[TMP1]], i32 0
+; CHECK-NEXT:    [[TMP2:%.*]] = extractelement <2 x float> [[TMP0]], i32 1
+; CHECK-NEXT:    [[RES2:%.*]] = insertelement <2 x float> [[RES1]], float [[TMP2]], i32 1
+; CHECK-NEXT:    ret <2 x float> [[RES2]]
+;
+entry:
+  %source = insertelement <2 x float> undef, float undef, i32 0
+  %e0 = extractelement <2 x float> %source, i32 0
+  %e0.dup = extractelement <2 x float> %source, i32 0
+  %sub1 = fsub float %e0, %e0.dup
+  %e1 = extractelement <2 x float> %source, i32 1
+  %e1.dup = extractelement <2 x float> %source, i32 1
+  %sub2 = fsub float %e1, %e1.dup
+  %res1 = insertelement <2 x float> undef, float %sub1, i32 0
+  %res2 = insertelement <2 x float> %res1, float %sub2, i32 1
+  ret <2 x float> %res2
+}
+
+!llvm.ident = !{!0, !0}
+
+!0 = !{!"clang version 4.0.0 "}