[clang] [llvm] [AMDGPU] Match bitsin(typeof(x)) - popcnt(x) to s_bcnt0_i32 (PR #164847)

[Patrick Simmons via cfe-commits]

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@@ -0,0 +1,110 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 6
+; RUN: llc -mtriple=amdgcn -mcpu=gfx900 < %s | FileCheck %s
+
+define amdgpu_ps void @bcnt032_not_for_vregs(ptr addrspace(1) %out, ptr addrspace(1) %in) {
+; CHECK-LABEL: bcnt032_not_for_vregs:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    s_lshl_b32 s0, s0, 2
+; CHECK-NEXT:    v_add_co_u32_e32 v2, vcc, s0, v2
+; CHECK-NEXT:    v_addc_co_u32_e32 v3, vcc, 0, v3, vcc
+; CHECK-NEXT:    global_load_dword v2, v[2:3], off glc
+; CHECK-NEXT:    s_waitcnt vmcnt(0)
+; CHECK-NEXT:    v_bcnt_u32_b32 v2, v2, 0
+; CHECK-NEXT:    v_sub_u32_e32 v3, 32, v2
+; CHECK-NEXT:    ;;#ASMSTART
+; CHECK-NEXT:    ; use v3
+; CHECK-NEXT:    ;;#ASMEND
+; CHECK-NEXT:    global_store_dword v[0:1], v2, off
+; CHECK-NEXT:    s_endpgm
+  %tid = call i32 @llvm.amdgcn.workitem.id.x()
+  %gep = getelementptr inbounds i32, ptr addrspace(1) %in, i32 %tid
+  %val0 = load volatile i32, ptr addrspace(1) %gep
+  %result = call i32 @llvm.ctpop.i32(i32 %val0) nounwind readnone
+  %result2 = sub i32 32, %result
+  call void asm "; use $0", "s"(i32 %result2)
+  %cmp = icmp ne i32 %result2, 0
+  %zext = zext i1 %cmp to i32
+  store i32 %result, ptr addrspace(1) %out
+  ret void
+}
+
+define amdgpu_ps void @bcnt064_not_for_vregs(ptr addrspace(1) %out, ptr addrspace(1) %in) {
+; CHECK-LABEL: bcnt064_not_for_vregs:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    s_lshl_b32 s0, s0, 2
+; CHECK-NEXT:    v_add_co_u32_e32 v2, vcc, s0, v2
+; CHECK-NEXT:    v_addc_co_u32_e32 v3, vcc, 0, v3, vcc
+; CHECK-NEXT:    global_load_dwordx2 v[2:3], v[2:3], off glc
+; CHECK-NEXT:    s_waitcnt vmcnt(0)
+; CHECK-NEXT:    v_mov_b32_e32 v4, 0
+; CHECK-NEXT:    v_bcnt_u32_b32 v2, v2, 0
+; CHECK-NEXT:    v_bcnt_u32_b32 v3, v3, v2
+; CHECK-NEXT:    v_sub_co_u32_e32 v5, vcc, 64, v3
+; CHECK-NEXT:    v_subb_co_u32_e64 v6, s[0:1], 0, 0, vcc
+; CHECK-NEXT:    ;;#ASMSTART
+; CHECK-NEXT:    ; use v[5:6]
+; CHECK-NEXT:    ;;#ASMEND
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linuxrocks123 wrote:

Yikes!  Do you want to file the issue or should I?

https://github.com/llvm/llvm-project/pull/164847