[clang] [llvm] [NVPTX] Support __usAtomicCAS builtin (PR #99646)
via cfe-commits
cfe-commits at lists.llvm.org
Tue Aug 20 06:14:26 PDT 2024
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@@ -0,0 +1,216 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --default-march nvptx64 --version 5
+; RUN: llc < %s -march=nvptx64 -mcpu=sm_32 | FileCheck %s --check-prefixes=SM30,CHECK
+; RUN: %if ptxas %{ llc < %s -march=nvptx64 -mcpu=sm_32 | %ptxas-verify %}
+; RUN: llc < %s -march=nvptx64 -mcpu=sm_70 -mattr=+ptx63 | FileCheck %s --check-prefixes=SM70,CHECK
+; RUN: %if ptxas %{ llc < %s -march=nvptx64 -mcpu=sm_70 -mattr=+ptx63 | %ptxas-verify -arch=sm_70 %}
+
+; TODO: these are system scope, but are compiled to gpu scope..
+; TODO: these are seq_cst, but are compiled to relaxed..
+
+; CHECK-LABEL: relaxed_sys_i8
+define i8 @relaxed_sys_i8(ptr %addr, i8 %cmp, i8 %new) {
+; SM30-LABEL: relaxed_sys_i8(
+; SM30: {
+; SM30-NEXT: .reg .pred %p<3>;
+; SM30-NEXT: .reg .b16 %rs<2>;
+; SM30-NEXT: .reg .b32 %r<21>;
+; SM30-NEXT: .reg .b64 %rd<3>;
+; SM30-EMPTY:
+; SM30-NEXT: // %bb.0:
+; SM30-NEXT: ld.param.u8 %rs1, [relaxed_sys_i8_param_2];
+; SM30-NEXT: ld.param.u64 %rd2, [relaxed_sys_i8_param_0];
+; SM30-NEXT: and.b64 %rd1, %rd2, -4;
+; SM30-NEXT: cvt.u32.u64 %r9, %rd2;
+; SM30-NEXT: and.b32 %r10, %r9, 3;
+; SM30-NEXT: shl.b32 %r1, %r10, 3;
+; SM30-NEXT: mov.b32 %r11, 255;
+; SM30-NEXT: shl.b32 %r12, %r11, %r1;
+; SM30-NEXT: not.b32 %r2, %r12;
+; SM30-NEXT: cvt.u32.u16 %r13, %rs1;
+; SM30-NEXT: and.b32 %r14, %r13, 255;
+; SM30-NEXT: shl.b32 %r3, %r14, %r1;
+; SM30-NEXT: ld.param.u8 %r15, [relaxed_sys_i8_param_1];
+; SM30-NEXT: shl.b32 %r4, %r15, %r1;
+; SM30-NEXT: ld.u32 %r16, [%rd1];
+; SM30-NEXT: and.b32 %r20, %r16, %r2;
+; SM30-NEXT: $L__BB0_1: // %partword.cmpxchg.loop
+; SM30-NEXT: // =>This Inner Loop Header: Depth=1
+; SM30-NEXT: or.b32 %r17, %r20, %r3;
+; SM30-NEXT: or.b32 %r18, %r20, %r4;
+; SM30-NEXT: atom.cas.b32 %r7, [%rd1], %r18, %r17;
+; SM30-NEXT: setp.eq.s32 %p1, %r7, %r18;
+; SM30-NEXT: @%p1 bra $L__BB0_3;
+; SM30-NEXT: // %bb.2: // %partword.cmpxchg.failure
+; SM30-NEXT: // in Loop: Header=BB0_1 Depth=1
+; SM30-NEXT: and.b32 %r8, %r7, %r2;
+; SM30-NEXT: setp.ne.s32 %p2, %r20, %r8;
+; SM30-NEXT: mov.u32 %r20, %r8;
+; SM30-NEXT: @%p2 bra $L__BB0_1;
+; SM30-NEXT: $L__BB0_3: // %partword.cmpxchg.end
+; SM30-NEXT: st.param.b32 [func_retval0+0], %r13;
+; SM30-NEXT: ret;
+;
+; SM70-LABEL: relaxed_sys_i8(
+; SM70: {
+; SM70-NEXT: .reg .pred %p<3>;
+; SM70-NEXT: .reg .b16 %rs<17>;
+; SM70-NEXT: .reg .b32 %r<3>;
+; SM70-NEXT: .reg .b64 %rd<5>;
+; SM70-EMPTY:
+; SM70-NEXT: // %bb.0:
+; SM70-NEXT: ld.param.u8 %rs9, [relaxed_sys_i8_param_2];
+; SM70-NEXT: ld.param.u64 %rd2, [relaxed_sys_i8_param_0];
+; SM70-NEXT: and.b64 %rd1, %rd2, -2;
+; SM70-NEXT: ld.param.u8 %rs10, [relaxed_sys_i8_param_1];
+; SM70-NEXT: and.b64 %rd3, %rd2, 1;
+; SM70-NEXT: shl.b64 %rd4, %rd3, 3;
+; SM70-NEXT: cvt.u32.u64 %r1, %rd4;
+; SM70-NEXT: mov.u16 %rs11, 255;
+; SM70-NEXT: shl.b16 %rs12, %rs11, %r1;
+; SM70-NEXT: not.b16 %rs2, %rs12;
+; SM70-NEXT: shl.b16 %rs3, %rs9, %r1;
+; SM70-NEXT: shl.b16 %rs4, %rs10, %r1;
+; SM70-NEXT: ld.u16 %rs13, [%rd1];
+; SM70-NEXT: and.b16 %rs16, %rs13, %rs2;
+; SM70-NEXT: $L__BB0_1: // %partword.cmpxchg.loop
+; SM70-NEXT: // =>This Inner Loop Header: Depth=1
+; SM70-NEXT: or.b16 %rs14, %rs16, %rs3;
+; SM70-NEXT: or.b16 %rs15, %rs16, %rs4;
+; SM70-NEXT: atom.cas.b16 %rs7, [%rd1], %rs15, %rs14;
+; SM70-NEXT: setp.eq.s16 %p1, %rs7, %rs15;
+; SM70-NEXT: @%p1 bra $L__BB0_3;
+; SM70-NEXT: // %bb.2: // %partword.cmpxchg.failure
+; SM70-NEXT: // in Loop: Header=BB0_1 Depth=1
+; SM70-NEXT: and.b16 %rs8, %rs7, %rs2;
+; SM70-NEXT: setp.ne.s16 %p2, %rs16, %rs8;
+; SM70-NEXT: mov.u16 %rs16, %rs8;
+; SM70-NEXT: @%p2 bra $L__BB0_1;
+; SM70-NEXT: $L__BB0_3: // %partword.cmpxchg.end
+; SM70-NEXT: cvt.u32.u16 %r2, %rs9;
+; SM70-NEXT: st.param.b32 [func_retval0+0], %r2;
+; SM70-NEXT: ret;
+ %pairold = cmpxchg ptr %addr, i8 %cmp, i8 %new seq_cst seq_cst
----------------
gonzalobg wrote:
@Artem-B this is generating tests that I think are too precise and contain too much unrelated CHECKs, particularly given that the codegen for all of this is actually incorrect (system scope sequentially consistent `cmpxchg` is only generating device scope relaxed atomics) as the TODO's above mention.
The only interesting part of the check seems to be:
```
; CHECK: %partword.cmpxchg.loop
; CHECK: or.b16 ...
; CHECK: or.b16 ...;
; CHECK: atom.cas.b16 ...;
; CHECK: setp.eq.s16 ...;
; CHECK: @%p1 bra ...;
; CHECK: %partword.cmpxchg.failure
; CHECK: and.b16 %rs8, %rs7, %rs2;
; CHECK: setp.ne.s16 %p2, %rs16, %rs8;
; CGECK: bra
; CHECK: %partword.cmpxchg.end
; CHECK: cvt.u32.u16 %r2, %rs9;
```
in the i8 test, and the i16 test for SM older than 70 (since all the others just lower to a single cas).
I'm fine with merging this as is for now, but I think these tests need to be reverted afterwards, and the checks more carefully and portably added.
https://github.com/llvm/llvm-project/pull/99646
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