Canonicalize addrspacecast ConstExpr between different pointer types

As a follow-up to r210375 which canonicalizes addrspacecast
instructions, this patch canonicalizes addrspacecast constant
expressions.

Given clang uses ConstantExpr::getAddrSpaceCast to emit addrspacecast
cosntant expressions, this patch is also a step towards having the
frontend emit canonicalized addrspacecasts.

Piggyback a minor refactor in InstCombineCasts.cpp

Update three affected tests in addrspacecast-alias.ll,
access-non-generic.ll and constant-fold-gep.ll and added one new test in
constant-fold-address-space-pointer.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211004 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/test/Transforms/InstCombine/constant-fold-address-space-pointer.ll b/test/Transforms/InstCombine/constant-fold-address-space-pointer.ll
index 9f21d5419b7..7fac78a40f5 100644
--- a/test/Transforms/InstCombine/constant-fold-address-space-pointer.ll
+++ b/test/Transforms/InstCombine/constant-fold-address-space-pointer.ll
@@ -230,3 +230,13 @@ define i32 @constant_through_array_as_ptrs() {
   %b = load i32 addrspace(1)* %a, align 4
   ret i32 %b
 }
+
+@shared_mem = external addrspace(3) global [0 x i8]
+
+define float @canonicalize_addrspacecast(i32 %i) {
+; CHECK-LABEL: @canonicalize_addrspacecast
+; CHECK-NEXT: getelementptr inbounds float* addrspacecast (float addrspace(3)* bitcast ([0 x i8] addrspace(3)* @shared_mem to float addrspace(3)*) to float*), i32 %i
+  %p = getelementptr inbounds float* addrspacecast ([0 x i8] addrspace(3)* @shared_mem to float*), i32 %i
+  %v = load float* %p
+  ret float %v
+}