vendor/llvm/llvm-trunk-r240225

1 files changed, 26 insertions, 0 deletions

diff --git a/test/CodeGen/AMDGPU/bfe_uint.ll b/test/CodeGen/AMDGPU/bfe_uint.ll
new file mode 100644
index 0000000000000..32e3fc26106f4
--- /dev/null
+++ b/test/CodeGen/AMDGPU/bfe_uint.ll
@@ -0,0 +1,26 @@
+; RUN: llc < %s -march=r600 -mcpu=redwood | FileCheck %s
+
+; CHECK: {{^}}bfe_def:
+; CHECK: BFE_UINT
+define void @bfe_def(i32 addrspace(1)* %out, i32 %x) {
+entry:
+  %0 = lshr i32 %x, 5
+  %1 = and i32 %0, 15 ; 0xf
+  store i32 %1, i32 addrspace(1)* %out
+  ret void
+}
+
+; This program could be implemented using a BFE_UINT instruction, however
+; since the lshr constant + number of bits in the mask is >= 32, it can also be
+; implmented with a LSHR instruction, which is better, because LSHR has less
+; operands and requires less constants.
+
+; CHECK: {{^}}bfe_shift:
+; CHECK-NOT: BFE_UINT
+define void @bfe_shift(i32 addrspace(1)* %out, i32 %x) {
+entry:
+  %0 = lshr i32 %x, 16
+  %1 = and i32 %0, 65535 ; 0xffff
+  store i32 %1, i32 addrspace(1)* %out
+  ret void
+}