[llvm-bugs] [Bug 30660] New: [ARM] inefficient negation of bool

[via llvm-bugs]

https://llvm.org/bugs/show_bug.cgi?id=30660

            Bug ID: 30660
           Summary: [ARM] inefficient negation of bool
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: All
            Status: NEW
          Severity: normal
          Priority: P
         Component: Backend: ARM
          Assignee: unassignedbugs at nondot.org
          Reporter: spatel+llvm at rotateright.com
                CC: llvm-bugs at lists.llvm.org
    Classification: Unclassified

$ cat negate-i1.ll 
define i32 @select_neg1_or_0(i1 %a) {
  %b = sext i1 %a to i32
  ret i32 %b
}

$ ./llc -o - negate-i1.ll -mtriple=arm
    lsl    r0, r0, #31
    asr    r0, r0, #31
    mov    pc, lr


Should this be neg/rsb?

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