forked from OSchip/llvm-project
46 lines
1.5 KiB
LLVM
46 lines
1.5 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
|
|
; RUN: opt -passes=aggressive-instcombine -S < %s | FileCheck %s
|
|
|
|
;; C reproducers:
|
|
;; #include "stdio.h"
|
|
;; unsigned x;
|
|
;;
|
|
;; int test ()
|
|
;; {
|
|
;; static const char table[32] =
|
|
;; {
|
|
;; 0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
|
|
;; 31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
|
|
;; };
|
|
;; return table[((unsigned)((x & -x) * 0x077CB531U)) >> 27];
|
|
;; }
|
|
;;
|
|
|
|
@x = global i32 0, align 4
|
|
@.str = private constant [3 x i8] c"%u\00", align 1
|
|
@test.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 @test() {
|
|
; CHECK-LABEL: @test(
|
|
; CHECK-NEXT: entry:
|
|
; CHECK-NEXT: [[TMP0:%.*]] = load i32, i32* @x, align 4
|
|
; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.cttz.i32(i32 [[TMP0]], i1 true)
|
|
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[TMP0]], 0
|
|
; CHECK-NEXT: [[TMP3:%.*]] = select i1 [[TMP2]], i32 0, i32 [[TMP1]]
|
|
; CHECK-NEXT: [[TMP4:%.*]] = trunc i32 [[TMP3]] to i8
|
|
; CHECK-NEXT: [[CONV:%.*]] = zext i8 [[TMP4]] to i32
|
|
; CHECK-NEXT: ret i32 [[CONV]]
|
|
;
|
|
entry:
|
|
%0 = load i32, i32* @x, align 4
|
|
%sub = sub i32 0, %0
|
|
%and = and i32 %0, %sub
|
|
%mul = mul i32 %and, 125613361
|
|
%shr = lshr i32 %mul, 27
|
|
%idxprom = zext i32 %shr to i64
|
|
%arrayidx = getelementptr inbounds [32 x i8], [32 x i8]* @test.table, i64 0, i64 %idxprom
|
|
%1 = load i8, i8* %arrayidx, align 1
|
|
%conv = zext i8 %1 to i32
|
|
ret i32 %conv
|
|
}
|