; Test that the ffs* library call simplifier works correctly. ; ; RUN: opt < %s -instcombine -S | FileCheck %s ; RUN: opt < %s -mtriple i386-pc-linux -instcombine -S | FileCheck %s -check-prefix=CHECK-LINUX 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" declare i32 @ffs(i32) declare i32 @ffsl(i32) declare i32 @ffsll(i64) ; Check ffs(0) -> 0. define i32 @test_simplify1() { ; CHECK-LABEL: @test_simplify1( %ret = call i32 @ffs(i32 0) ret i32 %ret ; CHECK-NEXT: ret i32 0 } define i32 @test_simplify2() { ; CHECK-LINUX-LABEL: @test_simplify2( %ret = call i32 @ffsl(i32 0) ret i32 %ret ; CHECK-LINUX-NEXT: ret i32 0 } define i32 @test_simplify3() { ; CHECK-LINUX-LABEL: @test_simplify3( %ret = call i32 @ffsll(i64 0) ret i32 %ret ; CHECK-LINUX-NEXT: ret i32 0 } ; Check ffs(c) -> cttz(c) + 1, where 'c' is a constant. define i32 @test_simplify4() { ; CHECK-LABEL: @test_simplify4( %ret = call i32 @ffs(i32 1) ret i32 %ret ; CHECK-NEXT: ret i32 1 } define i32 @test_simplify5() { ; CHECK-LABEL: @test_simplify5( %ret = call i32 @ffs(i32 2048) ret i32 %ret ; CHECK-NEXT: ret i32 12 } define i32 @test_simplify6() { ; CHECK-LABEL: @test_simplify6( %ret = call i32 @ffs(i32 65536) ret i32 %ret ; CHECK-NEXT: ret i32 17 } define i32 @test_simplify7() { ; CHECK-LINUX-LABEL: @test_simplify7( %ret = call i32 @ffsl(i32 65536) ret i32 %ret ; CHECK-LINUX-NEXT: ret i32 17 } define i32 @test_simplify8() { ; CHECK-LINUX-LABEL: @test_simplify8( %ret = call i32 @ffsll(i64 1024) ret i32 %ret ; CHECK-LINUX-NEXT: ret i32 11 } define i32 @test_simplify9() { ; CHECK-LINUX-LABEL: @test_simplify9( %ret = call i32 @ffsll(i64 65536) ret i32 %ret ; CHECK-LINUX-NEXT: ret i32 17 } define i32 @test_simplify10() { ; CHECK-LINUX-LABEL: @test_simplify10( %ret = call i32 @ffsll(i64 17179869184) ret i32 %ret ; CHECK-LINUX-NEXT: ret i32 35 } define i32 @test_simplify11() { ; CHECK-LINUX-LABEL: @test_simplify11( %ret = call i32 @ffsll(i64 281474976710656) ret i32 %ret ; CHECK-LINUX-NEXT: ret i32 49 } define i32 @test_simplify12() { ; CHECK-LINUX-LABEL: @test_simplify12( %ret = call i32 @ffsll(i64 1152921504606846976) ret i32 %ret ; CHECK-LINUX-NEXT: ret i32 61 } ; Check ffs(x) -> x != 0 ? (i32)llvm.cttz(x) + 1 : 0. define i32 @test_simplify13(i32 %x) { ; CHECK-LABEL: @test_simplify13( %ret = call i32 @ffs(i32 %x) ; CHECK-NEXT: [[CTTZ:%[a-z0-9]+]] = call i32 @llvm.cttz.i32(i32 %x, i1 false) ; CHECK-NEXT: [[INC:%[a-z0-9]+]] = add i32 [[CTTZ]], 1 ; CHECK-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i32 %x, 0 ; CHECK-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[INC]], i32 0 ret i32 %ret ; CHECK-NEXT: ret i32 [[RET]] } define i32 @test_simplify14(i32 %x) { ; CHECK-LINUX-LABEL: @test_simplify14( %ret = call i32 @ffsl(i32 %x) ; CHECK-LINUX-NEXT: [[CTTZ:%[a-z0-9]+]] = call i32 @llvm.cttz.i32(i32 %x, i1 false) ; CHECK-LINUX-NEXT: [[INC:%[a-z0-9]+]] = add i32 [[CTTZ]], 1 ; CHECK-LINUX-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i32 %x, 0 ; CHECK-LINUX-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[INC]], i32 0 ret i32 %ret ; CHECK-LINUX-NEXT: ret i32 [[RET]] } define i32 @test_simplify15(i64 %x) { ; CHECK-LINUX-LABEL: @test_simplify15( %ret = call i32 @ffsll(i64 %x) ; CHECK-LINUX-NEXT: [[CTTZ:%[a-z0-9]+]] = call i64 @llvm.cttz.i64(i64 %x, i1 false) ; CHECK-LINUX-NEXT: [[INC:%[a-z0-9]+]] = add i64 [[CTTZ]], 1 ; CHECK-LINUX-NEXT: [[TRUNC:%[a-z0-9]+]] = trunc i64 [[INC]] to i32 ; CHECK-LINUX-NEXT: [[CMP:%[a-z0-9]+]] = icmp ne i64 %x, 0 ; CHECK-LINUX-NEXT: [[RET:%[a-z0-9]+]] = select i1 [[CMP]], i32 [[TRUNC]], i32 0 ret i32 %ret ; CHECK-LINUX-NEXT: ret i32 [[RET]] }