[llvm] [InstCombine] Relax guard against FP min/max in select fold (PR #143144)

[Yingwei Zheng via llvm-commits]

================
@@ -268,3 +268,14 @@ define i1 @test_fcmp_select_var_const_unordered(double %x, double %y) {
   %cmp2 = fcmp ugt double %sel, 0x3E80000000000000
   ret i1 %cmp2
 }
+
+define i1 @test_fcmp_ord_select_fcmp_oeq_var_const(double %x) {
+; CHECK-LABEL:    @test_fcmp_ord_select_fcmp_oeq_var_const(
+; CHECK-NEXT:     [[CMP1:%.*]] = fcmp oeq double [[X:%.*]], 0.000000e+00
----------------
dtcxzyw wrote:

```suggestion
; CHECK-NEXT:     [[CMP1:%.*]] = fcmp oeq double [[X:%.*]], 1.000000e+00
```
******************** TEST 'LLVM :: Transforms/InstCombine/fcmp-select.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/opt < /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/Transforms/InstCombine/fcmp-select.ll -passes=instcombine -S | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/Transforms/InstCombine/fcmp-select.ll # RUN: at line 2
+ /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/opt -passes=instcombine -S
+ /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/Transforms/InstCombine/fcmp-select.ll
/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/Transforms/InstCombine/fcmp-select.ll:274:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: [[CMP1:%.*]] = fcmp oeq double [[X:%.*]], 0.000000e+00
              ^
<stdin>:135:52: note: scanning from here
define i1 @test_fcmp_ord_select_fcmp_oeq_var_const(double %x) {
                                                   ^
<stdin>:136:2: note: possible intended match here
 %1 = fcmp oeq double %x, 1.000000e+00
 ^

Input file: <stdin>
Check file: /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/Transforms/InstCombine/fcmp-select.ll

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

Input was:
<<<<<<
            .
            .
            .
          130:  %1 = fcmp ugt double %y, 0x3E80000000000000 
          131:  %cmp2 = select i1 %cmp1, i1 %1, i1 false 
          132:  ret i1 %cmp2 
          133: } 
          134:  
          135: define i1 @test_fcmp_ord_select_fcmp_oeq_var_const(double %x) { 
next:274'0                                                        X~~~~~~~~~~~~ error: no match found
          136:  %1 = fcmp oeq double %x, 1.000000e+00 
next:274'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
next:274'1      ?                                      possible intended match
          137:  ret i1 %1 
next:274'0     ~~~~~~~~~~~
          138: } 
next:274'0     ~~
          139:  
next:274'0     ~
          140: ; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none) 
next:274'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          141: declare double @llvm.maxnum.f64(double, double) #0 
next:274'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
            .
            .
            .
>>>>>>

--

********************

https://github.com/llvm/llvm-project/pull/143144