[PATCH] D14670: Fix bug 25440: GVN assertion after coercing loads

[Weiming Zhao via llvm-commits]

weimingz added inline comments.

================
Comment at: lib/Transforms/Scalar/GVN.cpp:1152
@@ -1140,2 +1151,3 @@
+  if (SrcVal->getType()->getScalarType()->isPointerTy()) {
     SrcVal = Builder.CreatePtrToInt(SrcVal,
         DL.getIntPtrType(SrcVal->getType()));
----------------
creates PtrToInt here, but has the same VN as %sub.ptr.rhs.cast25

================
Comment at: test/Transforms/GVN/pr25440.ll:80
@@ +79,3 @@
+if.then.14:                                       ; preds = %while.end, %while.bodythread-pre-split
+  %v1 = load i32, i32* bitcast (i8** @dfg_text to i32*), align 4
+  %sub.ptr.sub = sub i32 undef, %v1
----------------
try to do PRE here

================
Comment at: test/Transforms/GVN/pr25440.ll:93
@@ +92,3 @@
+  %add.ptr = getelementptr inbounds i8, i8* %v2, i32 undef
+  store i8* %add.ptr, i8** @dfg_text, align 4
+  %sub.ptr.rhs.cast25 = ptrtoint i8* %add.ptr to i32
----------------
finds the load with same addr

================
Comment at: test/Transforms/GVN/pr25440.ll:94
@@ +93,3 @@
+  store i8* %add.ptr, i8** @dfg_text, align 4
+  %sub.ptr.rhs.cast25 = ptrtoint i8* %add.ptr to i32
+  %sub.ptr.sub26 = sub i32 0, %sub.ptr.rhs.cast25
----------------
newly created ptrToInt has the same value, but inserted after it.


http://reviews.llvm.org/D14670