[llvm] r195773 - PR18060 - When we RAUW values with ExtractElement instructions in some cases

[Nadav Rotem]

Author: nadav
Date: Tue Nov 26 11:29:19 2013
New Revision: 195773

URL: http://llvm.org/viewvc/llvm-project?rev=195773&view=rev
Log:
PR18060 - When we RAUW values with ExtractElement instructions in some cases
we generate PHI nodes with multiple entries from the same basic block but
with different values. Enabling CSE on ExtractElement instructions make sure
that all of the RAUWed instructions are the same.


Added:
    llvm/trunk/test/Transforms/SLPVectorizer/X86/pr18060.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=195773&r1=195772&r2=195773&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp Tue Nov 26 11:29:19 2013
@@ -1591,6 +1591,8 @@ Value *BoUpSLP::vectorizeTree() {
     if (PHINode *PN = dyn_cast<PHINode>(Vec)) {
       Builder.SetInsertPoint(PN->getParent()->getFirstInsertionPt());
       Value *Ex = Builder.CreateExtractElement(Vec, Lane);
+      if (Instruction *Ins = dyn_cast<Instruction>(Ex))
+        GatherSeq.insert(Ins);
       User->replaceUsesOfWith(Scalar, Ex);
     } else if (isa<Instruction>(Vec)){
       if (PHINode *PH = dyn_cast<PHINode>(User)) {
@@ -1598,17 +1600,23 @@ Value *BoUpSLP::vectorizeTree() {
           if (PH->getIncomingValue(i) == Scalar) {
             Builder.SetInsertPoint(PH->getIncomingBlock(i)->getTerminator());
             Value *Ex = Builder.CreateExtractElement(Vec, Lane);
+            if (Instruction *Ins = dyn_cast<Instruction>(Ex))
+              GatherSeq.insert(Ins);
             PH->setOperand(i, Ex);
           }
         }
       } else {
         Builder.SetInsertPoint(cast<Instruction>(User));
         Value *Ex = Builder.CreateExtractElement(Vec, Lane);
+        if (Instruction *Ins = dyn_cast<Instruction>(Ex))
+          GatherSeq.insert(Ins);
         User->replaceUsesOfWith(Scalar, Ex);
      }
     } else {
       Builder.SetInsertPoint(F->getEntryBlock().begin());
       Value *Ex = Builder.CreateExtractElement(Vec, Lane);
+      if (Instruction *Ins = dyn_cast<Instruction>(Ex))
+        GatherSeq.insert(Ins);
       User->replaceUsesOfWith(Scalar, Ex);
     }
 

Added: llvm/trunk/test/Transforms/SLPVectorizer/X86/pr18060.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SLPVectorizer/X86/pr18060.ll?rev=195773&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SLPVectorizer/X86/pr18060.ll (added)
+++ llvm/trunk/test/Transforms/SLPVectorizer/X86/pr18060.ll Tue Nov 26 11:29:19 2013
@@ -0,0 +1,47 @@
+; RUN: opt < %s -basicaa -slp-vectorizer -dce -S -mtriple=x86_64-apple-macosx10.8.0 -mcpu=corei7
+
+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-f80:32:32-n8:16:32-S128"
+target triple = "i386-pc-linux"
+
+; Function Attrs: nounwind
+define i32 @_Z16adjustFixupValueyj(i64 %Value, i32 %Kind) {
+entry:
+  %extract.t = trunc i64 %Value to i32
+  %extract = lshr i64 %Value, 12
+  %extract.t6 = trunc i64 %extract to i32
+  switch i32 %Kind, label %sw.default [
+    i32 0, label %return
+    i32 1, label %return
+    i32 129, label %sw.bb1
+    i32 130, label %sw.bb2
+  ]
+
+sw.default:                                       ; preds = %entry
+  call void @_Z25llvm_unreachable_internalv()
+  unreachable
+
+sw.bb1:                                           ; preds = %entry
+  %shr = lshr i64 %Value, 16
+  %extract.t5 = trunc i64 %shr to i32
+  %extract7 = lshr i64 %Value, 28
+  %extract.t8 = trunc i64 %extract7 to i32
+  br label %sw.bb2
+
+sw.bb2:                                           ; preds = %sw.bb1, %entry
+  %Value.addr.0.off0 = phi i32 [ %extract.t, %entry ], [ %extract.t5, %sw.bb1 ]
+  %Value.addr.0.off12 = phi i32 [ %extract.t6, %entry ], [ %extract.t8, %sw.bb1 ]
+  %conv6 = and i32 %Value.addr.0.off0, 4095
+  %conv4 = shl i32 %Value.addr.0.off12, 16
+  %shl = and i32 %conv4, 983040
+  %or = or i32 %shl, %conv6
+  %or11 = or i32 %or, 8388608
+  br label %return
+
+return:                                           ; preds = %sw.bb2, %entry, %entry
+  %retval.0 = phi i32 [ %or11, %sw.bb2 ], [ %extract.t, %entry ], [ %extract.t, %entry ]
+  ret i32 %retval.0
+}
+
+; Function Attrs: noreturn
+declare void @_Z25llvm_unreachable_internalv()
+