[llvm] [AMDGPU] Add intrinsic exposing s_alloc_vgpr (PR #163951)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Linux-->
# :penguin: Linux x64 Test Results

* 166977 tests passed
* 2922 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### LLVM
<details>
<summary>LLVM.CodeGen/AMDGPU/intrinsic-amdgcn-s-alloc-vgpr.ll</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 2
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llc -global-isel=1 -mtriple=amdgcn--amdpal -mcpu=gfx1250 < /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AMDGPU/intrinsic-amdgcn-s-alloc-vgpr.ll | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AMDGPU/intrinsic-amdgcn-s-alloc-vgpr.ll --check-prefix=GISEL
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llc -global-isel=1 -mtriple=amdgcn--amdpal -mcpu=gfx1250
# note: command had no output on stdout or stderr
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AMDGPU/intrinsic-amdgcn-s-alloc-vgpr.ll --check-prefix=GISEL
# .---command stderr------------
# | /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AMDGPU/intrinsic-amdgcn-s-alloc-vgpr.ll:10:15: error: GISEL-NEXT: is not on the line after the previous match
# | ; GISEL-NEXT: s_alloc_vgpr 45
# |               ^
# | <stdin>:9:2: note: 'next' match was here
# |  s_alloc_vgpr 45
# |  ^
# | <stdin>:7:18: note: previous match ended here
# | ; %bb.0: ; %entry
# |                  ^
# | <stdin>:8:1: note: non-matching line after previous match is here
# |  s_setreg_imm32_b32 hwreg(HW_REG_WAVE_MODE, 25, 1), 1
# | ^
# | /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AMDGPU/intrinsic-amdgcn-s-alloc-vgpr.ll:36:15: error: GISEL-NEXT: is not on the line after the previous match
# | ; GISEL-NEXT: s_alloc_vgpr s0
# |               ^
# | <stdin>:60:2: note: 'next' match was here
# |  s_alloc_vgpr s0
# |  ^
# | <stdin>:58:18: note: previous match ended here
# | ; %bb.0: ; %entry
# |                  ^
# | <stdin>:59:1: note: non-matching line after previous match is here
# |  s_setreg_imm32_b32 hwreg(HW_REG_WAVE_MODE, 25, 1), 1
# | ^
# | 
# | Input file: <stdin>
# | Check file: /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/CodeGen/AMDGPU/intrinsic-amdgcn-s-alloc-vgpr.ll
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |          1:  .amdgcn_target "amdgcn-unknown-amdpal--gfx1250" 
# |          2:  .text 
# |          3:  .globl test_alloc_vreg_const ; -- Begin function test_alloc_vreg_const 
# |          4:  .p2align 8 
# |          5:  .type test_alloc_vreg_const, at function 
# |          6: test_alloc_vreg_const: ; @test_alloc_vreg_const 
# |          7: ; %bb.0: ; %entry 
# |          8:  s_setreg_imm32_b32 hwreg(HW_REG_WAVE_MODE, 25, 1), 1 
# |          9:  s_alloc_vgpr 45 
# | next:10      !~~~~~~~~~~~~~~  error: match on wrong line
# |         10:  s_cselect_b32 s0, 1, 0 
# |         11:  s_delay_alu instid0(SALU_CYCLE_1) | instskip(NEXT) | instid1(SALU_CYCLE_1) 
# |         12:  s_and_b32 s0, s0, 1 
# |         13:  v_mov_b32_e32 v2, s0 
# |         14:  global_store_b32 v[0:1], v2, off 
# |          .
# |          .
# |          .
# |         55:  .p2align 8 
# |         56:  .type test_alloc_vreg_var, at function 
# |         57: test_alloc_vreg_var: ; @test_alloc_vreg_var 
# |         58: ; %bb.0: ; %entry 
# |         59:  s_setreg_imm32_b32 hwreg(HW_REG_WAVE_MODE, 25, 1), 1 
# |         60:  s_alloc_vgpr s0 
# | next:36      !~~~~~~~~~~~~~~  error: match on wrong line
# |         61:  s_cselect_b32 s0, 1, 0 
# |         62:  s_delay_alu instid0(SALU_CYCLE_1) | instskip(NEXT) | instid1(SALU_CYCLE_1) 
# |         63:  s_and_b32 s0, s0, 1 
# |         64:  v_mov_b32_e32 v2, s0 
# |         65:  global_store_b32 v[0:1], v2, off 
# |          .
# |          .
# |          .
# | >>>>>>
# `-----------------------------
# error: command failed with exit status: 1

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/163951