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llvm-6502/test/Transforms/InstCombine/ffs-1.ll
Rafael Espindola 2e1c072976 Revert "Add the nsw flag when we detect that an add will not signed overflow."
This reverts commit r210029.

It was not correctly handling cases where LHS and RHS had multiple but different
sign bits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210048 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-02 21:12:19 +00:00

135 lines
3.6 KiB
LLVM

; 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]]
}