[PATCH] D37215: [ValueTracking] improve reverse assumption inference

[Nikita Popov via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL368723: [ValueTracking] Improve reverse assumption inference (authored by nikic, committed by ).

Changed prior to commit:
  https://reviews.llvm.org/D37215?vs=212888&id=214867#toc

Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D37215/new/

https://reviews.llvm.org/D37215

Files:
  llvm/trunk/lib/Analysis/ValueTracking.cpp
  llvm/trunk/test/Transforms/InstCombine/assume_inevitable.ll


Index: llvm/trunk/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/trunk/lib/Analysis/ValueTracking.cpp
+++ llvm/trunk/lib/Analysis/ValueTracking.cpp
@@ -558,12 +558,18 @@
         return true;
   }
 
+  // Don't let an assume affect itself - this would cause the problems
+  // `isEphemeralValueOf` is trying to prevent, and it would also make
+  // the loop below go out of bounds.
+  if (Inv == CxtI)
+    return false;
+
   // The context comes first, but they're both in the same block. Make sure
   // there is nothing in between that might interrupt the control flow.
   for (BasicBlock::const_iterator I =
          std::next(BasicBlock::const_iterator(CxtI)), IE(Inv);
        I != IE; ++I)
-    if (!isSafeToSpeculativelyExecute(&*I) && !isAssumeLikeIntrinsic(&*I))
+    if (!isGuaranteedToTransferExecutionToSuccessor(&*I))
       return false;
 
   return !isEphemeralValueOf(Inv, CxtI);
Index: llvm/trunk/test/Transforms/InstCombine/assume_inevitable.ll
===================================================================
--- llvm/trunk/test/Transforms/InstCombine/assume_inevitable.ll
+++ llvm/trunk/test/Transforms/InstCombine/assume_inevitable.ll
@@ -8,10 +8,10 @@
 ; CHECK-LABEL: @assume_inevitable(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[M:%.*]] = alloca i64, align 8
-; CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* [[A:%.*]], align 4
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* [[A:%.*]], align 32
 ; CHECK-NEXT:    [[LOADRES:%.*]] = load i32, i32* [[B:%.*]], align 4
 ; CHECK-NEXT:    [[LOADRES2:%.*]] = call i32 @llvm.annotation.i32(i32 [[LOADRES]], i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str1, i64 0, i64 0), i32 2)
-; CHECK-NEXT:    store i32 [[LOADRES2]], i32* [[A]], align 4
+; CHECK-NEXT:    store i32 [[LOADRES2]], i32* [[A]], align 32
 ; CHECK-NEXT:    [[DUMMY_EQ:%.*]] = icmp ugt i32 [[LOADRES]], 42
 ; CHECK-NEXT:    tail call void @llvm.assume(i1 [[DUMMY_EQ]])
 ; CHECK-NEXT:    [[M_I8:%.*]] = bitcast i64* [[M]] to i8*


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