[llvm] [X86] Don't always separate conditions in `(br (and/or cond0, cond1))` into separate branches (PR #81689)

[via llvm-commits]

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@@ -265,17 +254,15 @@ return:
 define i32 @any_bits_clear_branch(i32 %P, i32 %Q) nounwind {
 ; CHECK-LABEL: any_bits_clear_branch:
 ; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    andl %esi, %edi
 ; CHECK-NEXT:    cmpl $-1, %edi
-; CHECK-NEXT:    jne .LBB14_2
-; CHECK-NEXT:  # %bb.1: # %entry
-; CHECK-NEXT:    cmpl $-1, %esi
-; CHECK-NEXT:    jne .LBB14_2
-; CHECK-NEXT:  # %bb.3: # %return
-; CHECK-NEXT:    movl $192, %eax
-; CHECK-NEXT:    retq
-; CHECK-NEXT:  .LBB14_2: # %bb1
+; CHECK-NEXT:    je .LBB14_2
+; CHECK-NEXT:  # %bb.1: # %bb1
 ; CHECK-NEXT:    movl $4, %eax
 ; CHECK-NEXT:    retq
+; CHECK-NEXT:  .LBB14_2: # %return
+; CHECK-NEXT:    movl $192, %eax
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goldsteinn wrote:

Interestingly none of the new branches became `cmov`. I bet when we look for cmov this is still in `(and cond0, cond1)` and we only cmov on `setcc`.
Ill look into this.

https://github.com/llvm/llvm-project/pull/81689