[TargetLowering] Add test for bit comparison fold

This adds a test covering an issue in bit comparison folding.  The
issue will be addressed in the subsequent commit.

Patch by Erik Hogeman.

Differential Revision: https://reviews.llvm.org/D89390

diff --git a/llvm/test/CodeGen/NVPTX/pow2_mask_cmp.ll b/llvm/test/CodeGen/NVPTX/pow2_mask_cmp.ll
new file mode 100644 (file)
index 0000000..13e35d9
--- /dev/null
+++ b/llvm/test/CodeGen/NVPTX/pow2_mask_cmp.ll
@@ -0,0 +1,13 @@
+; RUN: llc -march=nvptx -verify-machineinstrs < %s | FileCheck %s
+
+; Tests the following pattern:
+; (X & 8) != 0 --> (X & 8) >> 3
+
+; CHECK-LABEL: @pow2_mask_cmp
+; CHECK: bfe.u32 {{%r[0-9]+}}, {{%r[0-9]+}}, 3, 1
+define i32 @pow2_mask_cmp(i32 %x) {
+  %a = and i32 %x, 8
+  %cmp = icmp ne i32 %a, 0
+  %r = zext i1 %cmp to i32
+  ret i32 %r
+}