llvm/test/CodeGen/NVPTX/pow2_mask_cmp.ll

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
; RUN: llc -mtriple=nvptx64 -verify-machineinstrs < %s | FileCheck %s
; RUN: %if ptxas %{ llc -mtriple=nvptx64 -verify-machineinstrs < %s | %ptxas-verify %}

; Tests the following pattern:
; (X & 8) != 0 --> (X & 8) >> 3

; This produces incorrect code in general when boolean false is
; represented as a negative one. There is however a special
; case when the type has a bitsize of 1, for which the false
; value will be identical regardless of the boolean representation.
; Check that the optimization triggers in this case.

define i32 @pow2_mask_cmp(i32 %x) {
; CHECK-LABEL: pow2_mask_cmp(
; CHECK:       {
; CHECK-NEXT:    .reg .b16 %rs<3>;
; CHECK-NEXT:    .reg .b32 %r<3>;
; CHECK-EMPTY:
; CHECK-NEXT:  // %bb.0:
; CHECK-NEXT:    ld.param.b8 %rs1, [pow2_mask_cmp_param_0];
; CHECK-NEXT:    shr.u16 %rs2, %rs1, 3;
; CHECK-NEXT:    cvt.u32.u16 %r1, %rs2;
; CHECK-NEXT:    and.b32 %r2, %r1, 1;
; CHECK-NEXT:    st.param.b32 [func_retval0], %r2;
; CHECK-NEXT:    ret;
  %a = and i32 %x, 8
  %cmp = icmp ne i32 %a, 0
  %r = zext i1 %cmp to i32
  ret i32 %r
}