[Mlir-commits] [mlir] [mlir][LLVM] Switch `undef` for `poison` for uninitialized values (PR #125629)

[LLVM Continuous Integration]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-flang-rhel-clang` running on `ppc64le-flang-rhel-test` while building `mlir` at step 6 "test-build-unified-tree-check-flang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/157/builds/19372

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

```
Step 6 (test-build-unified-tree-check-flang) failure: test (failure)
******************** TEST 'Flang :: Lower/PowerPC/ppc-vec-splat-elem-order.f90' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/build/bin/flang -fc1 -flang-experimental-hlfir -emit-llvm /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/flang/test/Lower/PowerPC/ppc-vec-splat-elem-order.f90 -fno-ppc-native-vector-element-order -triple ppc64le-unknown-linux -o - | /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/build/bin/FileCheck --check-prefixes="LLVMIR" /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/flang/test/Lower/PowerPC/ppc-vec-splat-elem-order.f90
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/build/bin/flang -fc1 -flang-experimental-hlfir -emit-llvm /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/flang/test/Lower/PowerPC/ppc-vec-splat-elem-order.f90 -fno-ppc-native-vector-element-order -triple ppc64le-unknown-linux -o -
+ /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/build/bin/FileCheck --check-prefixes=LLVMIR /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/flang/test/Lower/PowerPC/ppc-vec-splat-elem-order.f90
/home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/flang/test/Lower/PowerPC/ppc-vec-splat-elem-order.f90:11:11: error: LLVMIR: expected string not found in input
! LLVMIR: %[[ins:.*]] = insertelement <4 x float> undef, float %[[ele]], i32 0
          ^
<stdin>:9:43: note: scanning from here
 %4 = extractelement <4 x float> %3, i64 3
                                          ^
<stdin>:9:43: note: with "ele" equal to "4"
 %4 = extractelement <4 x float> %3, i64 3
                                          ^
<stdin>:10:2: note: possible intended match here
 %5 = insertelement <4 x float> poison, float %4, i32 0
 ^

Input file: <stdin>
Check file: /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/llvm-project/flang/test/Lower/PowerPC/ppc-vec-splat-elem-order.f90

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

Input was:
<<<<<<
            1: ; ModuleID = 'FIRModule' 
            2: source_filename = "FIRModule" 
            3: target datalayout = "e-m:e-Fn32-i64:64-i128:128-n32:64-S128-v256:256:256-v512:512:512" 
            4: target triple = "ppc64le-unknown-linux" 
            5:  
            6: define void @vec_splat_testf32i64_(ptr captures(none) %0) #0 { 
            7:  %2 = alloca <4 x float>, i64 1, align 16 
            8:  %3 = load <4 x float>, ptr %0, align 16 
            9:  %4 = extractelement <4 x float> %3, i64 3 
check:11'0                                               X error: no match found
check:11'1                                                 with "ele" equal to "4"
           10:  %5 = insertelement <4 x float> poison, float %4, i32 0 
check:11'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
check:11'2      ?                                                       possible intended match
           11:  %6 = shufflevector <4 x float> %5, <4 x float> poison, <4 x i32> zeroinitializer 
check:11'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           12:  store <4 x float> %6, ptr %2, align 16 
check:11'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           13:  ret void 
check:11'0     ~~~~~~~~~~
           14: } 
check:11'0     ~~
...

```

</details>

https://github.com/llvm/llvm-project/pull/125629