[PATCH] D32453: [InstCombine] Prevent InstCombine from triggering an extra iteration if something changed in the initial Worklist creation

[Phabricator via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL302982: [InstCombine] Prevent InstCombine from triggering an extra iteration if… (authored by ctopper).

Changed prior to commit:
  https://reviews.llvm.org/D32453?vs=96463&id=98877#toc

Repository:
  rL LLVM

https://reviews.llvm.org/D32453

Files:
  llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
  llvm/trunk/test/Transforms/InstCombine/constant-fold-iteration.ll


Index: llvm/trunk/test/Transforms/InstCombine/constant-fold-iteration.ll
===================================================================
--- llvm/trunk/test/Transforms/InstCombine/constant-fold-iteration.ll
+++ llvm/trunk/test/Transforms/InstCombine/constant-fold-iteration.ll
@@ -0,0 +1,10 @@
+; RUN: opt < %s -instcombine -S -debug 2>&1 | FileCheck %s
+; REQUIRES: asserts
+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"
+
+define i32 @a() nounwind readnone {
+entry:
+  ret i32 zext (i1 icmp eq (i32 0, i32 ptrtoint (i32 ()* @a to i32)) to i32)
+}
+; CHECK: INSTCOMBINE ITERATION #1
+; CHECK-NOT: INSTCOMBINE ITERATION #2
Index: llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
===================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -3141,27 +3141,26 @@
 
   // Lower dbg.declare intrinsics otherwise their value may be clobbered
   // by instcombiner.
-  bool DbgDeclaresChanged = LowerDbgDeclare(F);
+  bool MadeIRChange = LowerDbgDeclare(F);
 
   // Iterate while there is work to do.
   int Iteration = 0;
   for (;;) {
     ++Iteration;
     DEBUG(dbgs() << "\n\nINSTCOMBINE ITERATION #" << Iteration << " on "
                  << F.getName() << "\n");
 
-    bool Changed = prepareICWorklistFromFunction(F, DL, &TLI, Worklist);
+    MadeIRChange |= prepareICWorklistFromFunction(F, DL, &TLI, Worklist);
 
     InstCombiner IC(Worklist, &Builder, F.optForMinSize(), ExpensiveCombines,
                     AA, AC, TLI, DT, DL, LI);
     IC.MaxArraySizeForCombine = MaxArraySize;
-    Changed |= IC.run();
 
-    if (!Changed)
+    if (!IC.run())
       break;
   }
 
-  return DbgDeclaresChanged || Iteration > 1;
+  return MadeIRChange || Iteration > 1;
 }
 
 PreservedAnalyses InstCombinePass::run(Function &F,


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D32453.98877.patch
Type: text/x-patch
Size: 1992 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20170513/9521a5c6/attachment.bin>