[InstCombine] Fix assertion when bitcast is converted to gep

When an aggregate contains an opaque type its size cannot be
determined. This triggers an "Invalid GetElementPtrInst indices for type" assert
in function checkGEPType. The fix suppresses the conversion in this case.

http://reviews.llvm.org/D20319

llvm-svn: 270479

1 files changed, 32 insertions, 0 deletions

diff --git a/llvm/test/Transforms/InstCombine/opaque.ll b/llvm/test/Transforms/InstCombine/opaque.ll
new file mode 100644
index 00000000000..f2a91855d5a
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/opaque.ll
@@ -0,0 +1,32 @@
+; RUN: opt < %s -instcombine -disable-output
+; Checks that bitcasts are not converted into GEP when
+; when the size of an aggregate cannot be determined.
+%swift.opaque = type opaque
+%SQ = type <{ [8 x i8] }>
+%Si = type <{ i64 }>
+
+%V = type <{ <{ %Vs4Int8, %Vs4Int8, %Vs4Int8, %Vs4Int8, %Vs4Int8, %Vs4Int8, %Vs4Int8, %Vs4Int8 }>, %Si, %SQ, %SQ, %Si, %swift.opaque }>
+%Vs4Int8 = type <{ i8 }>
+%swift.type = type { i64 }
+
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly,
+i64, i32, i1) #8
+
+@_swift_slowAlloc = external global i8* (i64, i64)*
+
+declare i8* @rt_swift_slowAlloc(i64, i64)
+
+define  %swift.opaque* @_TwTkV([24 x i8]* %dest, %swift.opaque* %src,
+%swift.type* %bios_boot_params) #0 {
+entry:
+  %0 = bitcast %swift.opaque* %src to %V*
+  %1 = call noalias i8* @rt_swift_slowAlloc(i64 40, i64 0) #11
+  %2 = bitcast [24 x i8]* %dest to i8**
+  store i8* %1, i8** %2, align 8
+  %3 = bitcast i8* %1 to %V*
+  %4 = bitcast %V* %3 to i8*
+  %5 = bitcast %V* %0 to i8*
+  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %4, i8* %5, i64 40, i32 1, i1 false)
+  %6 = bitcast %V* %3 to %swift.opaque*
+  ret %swift.opaque* %6
+}