1 ; Test that the ffs* library call simplifier works correctly. 2 ; 3 ; RUN: opt < %s -instcombine -S | FileCheck %s 4 ; RUN: opt < %s -mtriple i386-pc-linux -instcombine -S | FileCheck %s -check-prefix=CHECK-LINUX 5 6 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128" 7 8 declare i32 @ffs(i32) 9 declare i32 @ffsl(i32) 10 declare i32 @ffsll(i64) 11 12 ; Check ffs(0) -> 0. 13 14 define i32 @test_simplify1() { 15 ; CHECK-LABEL: @test_simplify1( 16 %ret = call i32 @ffs(i32 0) 17 ret i32 %ret 18 ; CHECK-NEXT: ret i32 0 19 } 20 21 define i32 @test_simplify2() { 22 ; CHECK-LINUX-LABEL: @test_simplify2( 23 %ret = call i32 @ffsl(i32 0) 24 ret i32 %ret 25 ; CHECK-LINUX-NEXT: ret i32 0 26 } 27 28 define i32 @test_simplify3() { 29 ; CHECK-LINUX-LABEL: @test_simplify3( 30 %ret = call i32 @ffsll(i64 0) 31 ret i32 %ret 32 ; CHECK-LINUX-NEXT: ret i32 0 33 } 34 35 ; Check ffs(c) -> cttz(c) + 1, where 'c' is a constant. 36 37 define i32 @test_simplify4() { 38 ; CHECK-LABEL: @test_simplify4( 39 %ret = call i32 @ffs(i32 1) 40 ret i32 %ret 41 ; CHECK-NEXT: ret i32 1 42 } 43 44 define i32 @test_simplify5() { 45 ; CHECK-LABEL: @test_simplify5( 46 %ret = call i32 @ffs(i32 2048) 47 ret i32 %ret 48 ; CHECK-NEXT: ret i32 12 49 } 50 51 define i32 @test_simplify6() { 52 ; CHECK-LABEL: @test_simplify6( 53 %ret = call i32 @ffs(i32 65536) 54 ret i32 %ret 55 ; CHECK-NEXT: ret i32 17 56 } 57 58 define i32 @test_simplify7() { 59 ; CHECK-LINUX-LABEL: @test_simplify7( 60 %ret = call i32 @ffsl(i32 65536) 61 ret i32 %ret 62 ; CHECK-LINUX-NEXT: ret i32 17 63 } 64 65 define i32 @test_simplify8() { 66 ; CHECK-LINUX-LABEL: @test_simplify8( 67 %ret = call i32 @ffsll(i64 1024) 68 ret i32 %ret 69 ; CHECK-LINUX-NEXT: ret i32 11 70 } 71 72 define i32 @test_simplify9() { 73 ; CHECK-LINUX-LABEL: @test_simplify9( 74 %ret = call i32 @ffsll(i64 65536) 75 ret i32 %ret 76 ; CHECK-LINUX-NEXT: ret i32 17 77 } 78 79 define i32 @test_simplify10() { 80 ; CHECK-LINUX-LABEL: @test_simplify10( 81 %ret = call i32 @ffsll(i64 17179869184) 82 ret i32 %ret 83 ; CHECK-LINUX-NEXT: ret i32 35 84 } 85 86 define i32 @test_simplify11() { 87 ; CHECK-LINUX-LABEL: @test_simplify11( 88 %ret = call i32 @ffsll(i64 281474976710656) 89 ret i32 %ret 90 ; CHECK-LINUX-NEXT: ret i32 49 91 } 92 93 define i32 @test_simplify12() { 94 ; CHECK-LINUX-LABEL: @test_simplify12( 95 %ret = call i32 @ffsll(i64 1152921504606846976) 96 ret i32 %ret 97 ; CHECK-LINUX-NEXT: ret i32 61 98 } 99 100 ; Check ffs(x) -> x != 0 ? (i32)llvm.cttz(x) + 1 : 0. 101 102 define i32 @test_simplify13(i32 %x) { 103 ; CHECK-LABEL: @test_simplify13( 104 %ret = call i32 @ffs(i32 %x) 105 ; CHECK-NEXT: [[CTTZ:%[a-z0-9]+]] = call i32 @llvm.cttz.i32(i32 %x, i1 false) 106 ; CHECK-NEXT: [[INC:%[a-z0-9]+]] = add nuw nsw i32 [[CTTZ]], 1 107 ; CHECK-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i32 %x, 0 108 ; CHECK-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[INC]], i32 0 109 ret i32 %ret 110 ; CHECK-NEXT: ret i32 [[RET]] 111 } 112 113 define i32 @test_simplify14(i32 %x) { 114 ; CHECK-LINUX-LABEL: @test_simplify14( 115 %ret = call i32 @ffsl(i32 %x) 116 ; CHECK-LINUX-NEXT: [[CTTZ:%[a-z0-9]+]] = call i32 @llvm.cttz.i32(i32 %x, i1 false) 117 ; CHECK-LINUX-NEXT: [[INC:%[a-z0-9]+]] = add nuw nsw i32 [[CTTZ]], 1 118 ; CHECK-LINUX-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i32 %x, 0 119 ; CHECK-LINUX-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[INC]], i32 0 120 ret i32 %ret 121 ; CHECK-LINUX-NEXT: ret i32 [[RET]] 122 } 123 124 define i32 @test_simplify15(i64 %x) { 125 ; CHECK-LINUX-LABEL: @test_simplify15( 126 %ret = call i32 @ffsll(i64 %x) 127 ; CHECK-LINUX-NEXT: [[CTTZ:%[a-z0-9]+]] = call i64 @llvm.cttz.i64(i64 %x, i1 false) 128 ; CHECK-LINUX-NEXT: [[INC:%[a-z0-9]+]] = add nuw nsw i64 [[CTTZ]], 1 129 ; CHECK-LINUX-NEXT: [[TRUNC:%[a-z0-9]+]] = trunc i64 [[INC]] to i32 130 ; CHECK-LINUX-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i64 %x, 0 131 ; CHECK-LINUX-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[TRUNC]], i32 0 132 ret i32 %ret 133 ; CHECK-LINUX-NEXT: ret i32 [[RET]] 134 } 135
