File: lower-table-based-cttz-zero-element.ll

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llvm-toolchain-16 1%3A16.0.6-15~deb12u1
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -passes=aggressive-instcombine -S < %s | FileCheck %s

@ctz1.table = internal constant [32 x i8] c"\00\01\1C\02\1D\0E\18\03\1E\16\14\0F\19\11\04\08\1F\1B\0D\17\15\13\10\07\1A\0C\12\06\0B\05\0A\09", align 1

define i32 @ctz1(i32 %x) {
; CHECK-LABEL: @ctz1(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[TMP0:%.*]] = call i32 @llvm.cttz.i32(i32 [[X:%.*]], i1 true)
; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i32 [[X]], 0
; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP1]], i32 0, i32 [[TMP0]]
; CHECK-NEXT:    [[TMP3:%.*]] = trunc i32 [[TMP2]] to i8
; CHECK-NEXT:    [[CONV:%.*]] = zext i8 [[TMP3]] to i32
; CHECK-NEXT:    ret i32 [[CONV]]
;
entry:
  %sub = sub i32 0, %x
  %and = and i32 %sub, %x
  %mul = mul i32 %and, 125613361
  %shr = lshr i32 %mul, 27
  %idxprom = zext i32 %shr to i64
  %arrayidx = getelementptr inbounds [32 x i8], ptr @ctz1.table, i64 0, i64 %idxprom
  %0 = load i8, ptr %arrayidx, align 1
  %conv = zext i8 %0 to i32
  ret i32 %conv
}