SeparateConstOffsetFromGEP: Add baseline test for opaque pointers

This currently emits a pointless bitcast.

diff --git a/llvm/test/Transforms/SeparateConstOffsetFromGEP/AMDGPU/split-gep.ll b/llvm/test/Transforms/SeparateConstOffsetFromGEP/AMDGPU/split-gep.ll
new file mode 100644 (file)
index 0000000..743e1c2
--- /dev/null
+++ b/llvm/test/Transforms/SeparateConstOffsetFromGEP/AMDGPU/split-gep.ll
@@ -0,0 +1,27 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -mtriple=amdgcn-amd-amdhsa -passes=separate-const-offset-from-gep \
+; RUN:       -reassociate-geps-verify-no-dead-code -S | FileCheck %s
+
+%struct.Packed = type <{ [3 x i32], [8 x i64] }> ; <> means packed
+
+@packed_struct_array = addrspace(3) global [1024 x %struct.Packed] poison, align 1
+
+; Verifies we can emit correct uglygep if the address is not natually
+; aligned. This shoult not produce a no-op bitcast with opaque
+; pointers.
+define ptr addrspace(3) @packed_struct(i32 %i, i32 %j) {
+; CHECK-LABEL: @packed_struct(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = sext i32 [[I:%.*]] to i64
+; CHECK-NEXT:    [[TMP1:%.*]] = sext i32 [[J:%.*]] to i64
+; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr [1024 x %struct.Packed], ptr addrspace(3) @packed_struct_array, i64 0, i64 [[TMP0]], i32 1, i64 [[TMP1]]
+; CHECK-NEXT:    [[TMP3:%.*]] = bitcast ptr addrspace(3) [[TMP2]] to ptr addrspace(3)
+; CHECK-NEXT:    [[UGLYGEP:%.*]] = getelementptr inbounds i8, ptr addrspace(3) [[TMP3]], i64 100
+; CHECK-NEXT:    ret ptr addrspace(3) [[UGLYGEP]]
+;
+entry:
+  %add = add nsw i32 %j, 3
+  %add1 = add nsw i32 %i, 1
+  %arrayidx3 = getelementptr inbounds [1024 x %struct.Packed], ptr addrspace(3) @packed_struct_array, i64 0, i32 %add1, i32 1, i32 %add
+  ret ptr addrspace(3) %arrayidx3
+}