[CodeGen] Bitcast scalar writes to actual value.

The type of NewValue might change due to ScalarEvolution
looking though bitcasts. The synthesized NewValue therefore
becomes the type before the bitcast.

llvm-svn: 312718

2 files changed, 44 insertions, 0 deletions

diff --git a/polly/lib/CodeGen/BlockGenerators.cpp b/polly/lib/CodeGen/BlockGenerators.cpp
index 5988fc88da0..53b6f500997 100644
--- a/polly/lib/CodeGen/BlockGenerators.cpp
+++ b/polly/lib/CodeGen/BlockGenerators.cpp
@@ -692,6 +692,13 @@ void BlockGenerator::generateScalarStores(
                   DT.dominates(cast<Instruction>(Address)->getParent(),
                                Builder.GetInsertBlock())) &&
                  "Domination violation");
+
+          // The new Val might have a different type than the old Val due to
+          // ScalarEvolution looking through bitcasts.
+          if (Val->getType() != Address->getType()->getPointerElementType())
+            Address = Builder.CreateBitOrPointerCast(
+                Address, Val->getType()->getPointerTo());
+
           Builder.CreateStore(Val, Address);
 
         });
diff --git a/polly/test/Isl/CodeGen/scev_looking_through_bitcasts.ll b/polly/test/Isl/CodeGen/scev_looking_through_bitcasts.ll
new file mode 100644
index 00000000000..1012e23cd3a
--- /dev/null
+++ b/polly/test/Isl/CodeGen/scev_looking_through_bitcasts.ll
@@ -0,0 +1,37 @@
+; RUN: opt %loadPolly -polly-codegen -S < %s | FileCheck %s
+;
+; Scalar write of bitcasted value. Instead of writing %b of type
+; %structty, the SCEV expression looks through the bitcast such that
+; SCEVExpander returns %add.ptr81.i of type i8* to be the new value
+; of %b.
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+%structty = type { %structty*, %structty*, i32, [2 x i64] }
+
+define void @bitmap_set_range() {
+entry:
+  %a = ptrtoint i8* undef to i64
+  br label %cond.end32.i
+
+cond.end32.i:
+  br i1 false, label %cond.true67.i, label %cond.end73.i
+
+cond.true67.i:
+  br label %cond.end73.i
+
+cond.end73.i:
+  %add.ptr81.i = getelementptr inbounds i8, i8* null, i64 %a
+  %b = bitcast i8* %add.ptr81.i to %structty*
+  br label %bitmap_element_allocate.exit
+
+bitmap_element_allocate.exit:
+  %tobool43 = icmp eq %structty* %b, null
+  ret void
+}
+
+
+; CHECK:       polly.stmt.cond.end73.i:
+; CHECK-NEXT:   %0 = bitcast %structty** %b.s2a to i8**
+; CHECK-NEXT:   store i8* undef, i8** %0
+; CHECK-NEXT:   br label %polly.exiting