[llvm] r288968 - [GVNHoist] Invalidate MemDep when an instruction is moved.

[Eli Friedman via llvm-commits]

Author: efriedma
Date: Wed Dec  7 13:55:59 2016
New Revision: 288968

URL: http://llvm.org/viewvc/llvm-project?rev=288968&view=rev
Log:
[GVNHoist] Invalidate MemDep when an instruction is moved.

See also r279907.

Fixes https://llvm.org/bugs/show_bug.cgi?id=30991 .

Differential Revision: https://reviews.llvm.org/D27493


Modified:
    llvm/trunk/lib/Transforms/Scalar/GVNHoist.cpp
    llvm/trunk/test/Transforms/GVNHoist/hoist.ll

Modified: llvm/trunk/lib/Transforms/Scalar/GVNHoist.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVNHoist.cpp?rev=288968&r1=288967&r2=288968&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVNHoist.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/GVNHoist.cpp Wed Dec  7 13:55:59 2016
@@ -802,6 +802,7 @@ private:
 
         // Move the instruction at the end of HoistPt.
         Instruction *Last = HoistPt->getTerminator();
+        MD->removeInstruction(Repl);
         Repl->moveBefore(Last);
 
         DFSNumber[Repl] = DFSNumber[Last]++;

Modified: llvm/trunk/test/Transforms/GVNHoist/hoist.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVNHoist/hoist.ll?rev=288968&r1=288967&r2=288968&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVNHoist/hoist.ll (original)
+++ llvm/trunk/test/Transforms/GVNHoist/hoist.ll Wed Dec  7 13:55:59 2016
@@ -711,3 +711,36 @@ return:
 ; CHECK: %[[load:.*]] = load i32, i32* %y, align 1
 ; CHECK: %[[phi:.*]] = phi i32 [ %[[load]], %{{.*}} ], [ %[[load]], %{{.*}} ]
 ; CHECK: i32 %[[phi]]
+
+
+declare i8 @pr30991_f() nounwind readonly
+declare void @pr30991_f1(i8)
+define i8 @pr30991(i8* %sp, i8* %word, i1 %b1, i1 %b2) {
+entry:
+  br i1 %b1, label %a, label %b
+
+a:
+  %r0 = load i8, i8* %word, align 1
+  %incdec.ptr = getelementptr i8, i8* %sp, i32 1
+  %rr0 = call i8 @pr30991_f() nounwind readonly
+  call void @pr30991_f1(i8 %r0)
+  ret i8 %rr0
+
+b:
+  br i1 %b2, label %c, label %x
+
+c:
+  %r1 = load i8, i8* %word, align 1
+  %incdec.ptr115 = getelementptr i8, i8* %sp, i32 1
+  %rr1 = call i8 @pr30991_f() nounwind readonly
+  call void @pr30991_f1(i8 %r1)
+  ret i8 %rr1
+
+x:
+  %r2 = load i8, i8* %word, align 1
+  ret i8 %r2
+}
+
+; CHECK-LABEL: define i8 @pr30991
+; CHECK:  %r0 = load i8, i8* %word, align 1
+; CHECK-NEXT:  br i1 %b1, label %a, label %b