[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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291692 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp
index bcaa8439cffa50394c9315769e78f9416b1bd456..1c7cbc7edf9a310713da1e153906f983da35b53c 100644 (file)
--- a/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -2493,10 +2493,6 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E) {
       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;
 

diff --git a/test/Transforms/SLPVectorizer/X86/pr31599.ll b/test/Transforms/SLPVectorizer/X86/pr31599.ll
new file mode 100644 (file)
index 0000000..64e0f7b
--- /dev/null
+++ b/test/Transforms/SLPVectorizer/X86/pr31599.ll
@@ -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 "}