| ; 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, ptr @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, ptr @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], ptr @test.table, i64 0, i64 %idxprom |
| %1 = load i8, ptr %arrayidx, align 1 |
| %conv = zext i8 %1 to i32 |
| ret i32 %conv |
| } |
