[llvm] [X86] Eliminate redundant zero-extension instructions (PR #161401)

[Simon Pilgrim via llvm-commits]

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@@ -17,12 +17,11 @@ define i32 @countholes(ptr %s) {
 ; CHECK-NEXT:  # %bb.1: # %while.body.preheader
 ; CHECK-NEXT:    incq %rdi
 ; CHECK-NEXT:    xorl %eax, %eax
-; CHECK-NEXT:    leaq pre_table(%rip), %rdx
-; CHECK-NEXT:    .p2align 4, 0x90
+; CHECK-NEXT:    .p2align 4{{$}}
 ; CHECK-NEXT:  .LBB0_2: # %while.body
 ; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
-; CHECK-NEXT:    addl $-48, %ecx
-; CHECK-NEXT:    addl (%rdx,%rcx,4), %eax
+; CHECK-NOT:     movzbl %cl, %ecx
+; CHECK:         addl {{.*}}, %eax
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RKSimon wrote:

please just regenerate - non-sequential checks always make me nervous - like you're trying to hide bad codegen in between

https://github.com/llvm/llvm-project/pull/161401