[llvm] [AMDGPU] Detect trivially uniform arguments in InstCombine (PR #129897)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `premerge-monolithic-linux` running on `premerge-linux-1` while building `llvm` at step 7 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/153/builds/34217

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 7 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
/build/buildbot/premerge-monolithic-linux/build/bin/opt -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1010 -passes=instcombine -S < /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll | /build/buildbot/premerge-monolithic-linux/build/bin/FileCheck /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll # RUN: at line 2
+ /build/buildbot/premerge-monolithic-linux/build/bin/FileCheck /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll
+ /build/buildbot/premerge-monolithic-linux/build/bin/opt -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1010 -passes=instcombine -S
/build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll:6499:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: [[V:%.*]] = call i32 @llvm.amdgcn.readlane.i32(i32 [[SRC:%.*]], i32 7)
              ^
<stdin>:3619:54: note: scanning from here
define amdgpu_kernel void @ds_bpermute_constant_lane(ptr addrspace(1) %out, i32 %src) #3 {
                                                     ^
/build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll:6510:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: [[LANE:%.*]] = call i32 @llvm.amdgcn.readfirstlane.i32(i32 [[LANEARG:%.*]])
              ^
<stdin>:3624:53: note: scanning from here
define amdgpu_kernel void @ds_bpermute_uniform_lane(ptr addrspace(1) %out, i32 %lanearg, i32 %src) #3 {
                                                    ^
<stdin>:3624:66: note: possible intended match here
define amdgpu_kernel void @ds_bpermute_uniform_lane(ptr addrspace(1) %out, i32 %lanearg, i32 %src) #3 {
                                                                 ^

Input file: <stdin>
Check file: /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll

-dump-input=help explains the following input dump.

Input was:
<<<<<<
             .
             .
             .
          3614: define amdgpu_kernel void @ds_bpermute_uniform_src(ptr addrspace(1) %out, i32 %lane) #3 { 
          3615:  store i32 7, ptr addrspace(1) %out, align 4 
          3616:  ret void 
          3617: } 
          3618:  
          3619: define amdgpu_kernel void @ds_bpermute_constant_lane(ptr addrspace(1) %out, i32 %src) #3 { 
next:6499                                                            X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
          3620:  store i32 %src, ptr addrspace(1) %out, align 4 
next:6499       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          3621:  ret void 
next:6499       ~~~~~~~~~~
          3622: } 
next:6499       ~~
          3623:  
next:6499       ~
          3624: define amdgpu_kernel void @ds_bpermute_uniform_lane(ptr addrspace(1) %out, i32 %lanearg, i32 %src) #3 { 
...

```

</details>

https://github.com/llvm/llvm-project/pull/129897