llvm/test/Transforms/InstCombine/select-cmp-cttz-ctlz.ll
Andrea Di Biagio d25126faae [InstCombine] Fix regression introduced at r227197.
This patch fixes a problem I accidentally introduced in an instruction combine
on select instructions added at r227197. That revision taught the instruction
combiner how to fold a cttz/ctlz followed by a icmp plus select into a single
cttz/ctlz with flag 'is_zero_undef' cleared.

However, the new rule added at r227197 would have produced wrong results in the
case where a cttz/ctlz with flag 'is_zero_undef' cleared was follwed by a
zero-extend or truncate. In that case, the folded instruction would have
been inserted in a wrong location thus leaving the CFG in an inconsistent
state.

This patch fixes the problem and add two reproducible test cases to
existing test 'InstCombine/select-cmp-cttz-ctlz.ll'.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229124 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-13 16:33:34 +00:00

328 lines
9.8 KiB
LLVM

; RUN: opt -instcombine -S < %s | FileCheck %s
; This test is to verify that the instruction combiner is able to fold
; a cttz/ctlz followed by a icmp + select into a single cttz/ctlz with
; the 'is_zero_undef' flag cleared.
define i16 @test1(i16 %x) {
; CHECK-LABEL: @test1(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i16 @llvm.ctlz.i16(i16 %x, i1 false)
; CHECK-NEXT: ret i16 [[VAR]]
entry:
%0 = tail call i16 @llvm.ctlz.i16(i16 %x, i1 true)
%tobool = icmp ne i16 %x, 0
%cond = select i1 %tobool, i16 %0, i16 16
ret i16 %cond
}
define i32 @test2(i32 %x) {
; CHECK-LABEL: @test2(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i32 @llvm.ctlz.i32(i32 %x, i1 false)
; CHECK-NEXT: ret i32 [[VAR]]
entry:
%0 = tail call i32 @llvm.ctlz.i32(i32 %x, i1 true)
%tobool = icmp ne i32 %x, 0
%cond = select i1 %tobool, i32 %0, i32 32
ret i32 %cond
}
define i64 @test3(i64 %x) {
; CHECK-LABEL: @test3(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i64 @llvm.ctlz.i64(i64 %x, i1 false)
; CHECK-NEXT: ret i64 [[VAR]]
entry:
%0 = tail call i64 @llvm.ctlz.i64(i64 %x, i1 true)
%tobool = icmp ne i64 %x, 0
%cond = select i1 %tobool, i64 %0, i64 64
ret i64 %cond
}
define i16 @test4(i16 %x) {
; CHECK-LABEL: @test4(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i16 @llvm.ctlz.i16(i16 %x, i1 false)
; CHECK-NEXT: ret i16 [[VAR]]
entry:
%0 = tail call i16 @llvm.ctlz.i16(i16 %x, i1 true)
%tobool = icmp eq i16 %x, 0
%cond = select i1 %tobool, i16 16, i16 %0
ret i16 %cond
}
define i32 @test5(i32 %x) {
; CHECK-LABEL: @test5(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i32 @llvm.ctlz.i32(i32 %x, i1 false)
; CHECK-NEXT: ret i32 [[VAR]]
entry:
%0 = tail call i32 @llvm.ctlz.i32(i32 %x, i1 true)
%tobool = icmp eq i32 %x, 0
%cond = select i1 %tobool, i32 32, i32 %0
ret i32 %cond
}
define i64 @test6(i64 %x) {
; CHECK-LABEL: @test6(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i64 @llvm.ctlz.i64(i64 %x, i1 false)
; CHECK-NEXT: ret i64 [[VAR]]
entry:
%0 = tail call i64 @llvm.ctlz.i64(i64 %x, i1 true)
%tobool = icmp eq i64 %x, 0
%cond = select i1 %tobool, i64 64, i64 %0
ret i64 %cond
}
define i16 @test1b(i16 %x) {
; CHECK-LABEL: @test1b(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i16 @llvm.cttz.i16(i16 %x, i1 false)
; CHECK-NEXT: ret i16 [[VAR]]
entry:
%0 = tail call i16 @llvm.cttz.i16(i16 %x, i1 true)
%tobool = icmp ne i16 %x, 0
%cond = select i1 %tobool, i16 %0, i16 16
ret i16 %cond
}
define i32 @test2b(i32 %x) {
; CHECK-LABEL: @test2b(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i32 @llvm.cttz.i32(i32 %x, i1 false)
; CHECK-NEXT: ret i32 [[VAR]]
entry:
%0 = tail call i32 @llvm.cttz.i32(i32 %x, i1 true)
%tobool = icmp ne i32 %x, 0
%cond = select i1 %tobool, i32 %0, i32 32
ret i32 %cond
}
define i64 @test3b(i64 %x) {
; CHECK-LABEL: @test3b(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i64 @llvm.cttz.i64(i64 %x, i1 false)
; CHECK-NEXT: ret i64 [[VAR]]
entry:
%0 = tail call i64 @llvm.cttz.i64(i64 %x, i1 true)
%tobool = icmp ne i64 %x, 0
%cond = select i1 %tobool, i64 %0, i64 64
ret i64 %cond
}
define i16 @test4b(i16 %x) {
; CHECK-LABEL: @test4b(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i16 @llvm.cttz.i16(i16 %x, i1 false)
; CHECK-NEXT: ret i16 [[VAR]]
entry:
%0 = tail call i16 @llvm.cttz.i16(i16 %x, i1 true)
%tobool = icmp eq i16 %x, 0
%cond = select i1 %tobool, i16 16, i16 %0
ret i16 %cond
}
define i32 @test5b(i32 %x) {
; CHECK-LABEL: @test5b(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i32 @llvm.cttz.i32(i32 %x, i1 false)
; CHECK-NEXT: ret i32 [[VAR]]
entry:
%0 = tail call i32 @llvm.cttz.i32(i32 %x, i1 true)
%tobool = icmp eq i32 %x, 0
%cond = select i1 %tobool, i32 32, i32 %0
ret i32 %cond
}
define i64 @test6b(i64 %x) {
; CHECK-LABEL: @test6b(
; CHECK: [[VAR:%[a-zA-Z0-9]+]] = tail call i64 @llvm.cttz.i64(i64 %x, i1 false)
; CHECK-NEXT: ret i64 [[VAR]]
entry:
%0 = tail call i64 @llvm.cttz.i64(i64 %x, i1 true)
%tobool = icmp eq i64 %x, 0
%cond = select i1 %tobool, i64 64, i64 %0
ret i64 %cond
}
define i32 @test1c(i16 %x) {
; CHECK-LABEL: @test1c(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i16 @llvm.cttz.i16(i16 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = zext i16 [[VAR1]] to i32
; CHECK-NEXT: ret i32 [[VAR2]]
entry:
%0 = tail call i16 @llvm.cttz.i16(i16 %x, i1 true)
%cast2 = zext i16 %0 to i32
%tobool = icmp ne i16 %x, 0
%cond = select i1 %tobool, i32 %cast2, i32 16
ret i32 %cond
}
define i64 @test2c(i16 %x) {
; CHECK-LABEL: @test2c(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i16 @llvm.cttz.i16(i16 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = zext i16 [[VAR1]] to i64
; CHECK-NEXT: ret i64 [[VAR2]]
entry:
%0 = tail call i16 @llvm.cttz.i16(i16 %x, i1 true)
%conv = zext i16 %0 to i64
%tobool = icmp ne i16 %x, 0
%cond = select i1 %tobool, i64 %conv, i64 16
ret i64 %cond
}
define i64 @test3c(i32 %x) {
; CHECK-LABEL: @test3c(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i32 @llvm.cttz.i32(i32 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = zext i32 [[VAR1]] to i64
; CHECK-NEXT: ret i64 [[VAR2]]
entry:
%0 = tail call i32 @llvm.cttz.i32(i32 %x, i1 true)
%conv = zext i32 %0 to i64
%tobool = icmp ne i32 %x, 0
%cond = select i1 %tobool, i64 %conv, i64 32
ret i64 %cond
}
define i32 @test4c(i16 %x) {
; CHECK-LABEL: @test4c(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i16 @llvm.ctlz.i16(i16 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = zext i16 [[VAR1]] to i32
; CHECK-NEXT: ret i32 [[VAR2]]
entry:
%0 = tail call i16 @llvm.ctlz.i16(i16 %x, i1 true)
%cast = zext i16 %0 to i32
%tobool = icmp ne i16 %x, 0
%cond = select i1 %tobool, i32 %cast, i32 16
ret i32 %cond
}
define i64 @test5c(i16 %x) {
; CHECK-LABEL: @test5c(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i16 @llvm.ctlz.i16(i16 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = zext i16 [[VAR1]] to i64
; CHECK-NEXT: ret i64 [[VAR2]]
entry:
%0 = tail call i16 @llvm.ctlz.i16(i16 %x, i1 true)
%cast = zext i16 %0 to i64
%tobool = icmp ne i16 %x, 0
%cond = select i1 %tobool, i64 %cast, i64 16
ret i64 %cond
}
define i64 @test6c(i32 %x) {
; CHECK-LABEL: @test6c(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i32 @llvm.ctlz.i32(i32 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = zext i32 [[VAR1]] to i64
; CHECK-NEXT: ret i64 [[VAR2]]
entry:
%0 = tail call i32 @llvm.ctlz.i32(i32 %x, i1 true)
%cast = zext i32 %0 to i64
%tobool = icmp ne i32 %x, 0
%cond = select i1 %tobool, i64 %cast, i64 32
ret i64 %cond
}
define i16 @test1d(i64 %x) {
; CHECK-LABEL: @test1d(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i64 @llvm.cttz.i64(i64 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = trunc i64 [[VAR1]] to i16
; CHECK-NEXT: ret i16 [[VAR2]]
entry:
%0 = tail call i64 @llvm.cttz.i64(i64 %x, i1 true)
%conv = trunc i64 %0 to i16
%tobool = icmp ne i64 %x, 0
%cond = select i1 %tobool, i16 %conv, i16 64
ret i16 %cond
}
define i32 @test2d(i64 %x) {
; CHECK-LABEL: @test2d(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i64 @llvm.cttz.i64(i64 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = trunc i64 [[VAR1]] to i32
; CHECK-NEXT: ret i32 [[VAR2]]
entry:
%0 = tail call i64 @llvm.cttz.i64(i64 %x, i1 true)
%cast = trunc i64 %0 to i32
%tobool = icmp ne i64 %x, 0
%cond = select i1 %tobool, i32 %cast, i32 64
ret i32 %cond
}
define i16 @test3d(i32 %x) {
; CHECK-LABEL: @test3d(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i32 @llvm.cttz.i32(i32 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = trunc i32 [[VAR1]] to i16
; CHECK-NEXT: ret i16 [[VAR2]]
entry:
%0 = tail call i32 @llvm.cttz.i32(i32 %x, i1 true)
%cast = trunc i32 %0 to i16
%tobool = icmp ne i32 %x, 0
%cond = select i1 %tobool, i16 %cast, i16 32
ret i16 %cond
}
define i16 @test4d(i64 %x) {
; CHECK-LABEL: @test4d(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i64 @llvm.ctlz.i64(i64 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = trunc i64 [[VAR1]] to i16
; CHECK-NEXT: ret i16 [[VAR2]]
entry:
%0 = tail call i64 @llvm.ctlz.i64(i64 %x, i1 true)
%cast = trunc i64 %0 to i16
%tobool = icmp ne i64 %x, 0
%cond = select i1 %tobool, i16 %cast, i16 64
ret i16 %cond
}
define i32 @test5d(i64 %x) {
; CHECK-LABEL: @test5d(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i64 @llvm.ctlz.i64(i64 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = trunc i64 [[VAR1]] to i32
; CHECK-NEXT: ret i32 [[VAR2]]
entry:
%0 = tail call i64 @llvm.ctlz.i64(i64 %x, i1 true)
%cast = trunc i64 %0 to i32
%tobool = icmp ne i64 %x, 0
%cond = select i1 %tobool, i32 %cast, i32 64
ret i32 %cond
}
define i16 @test6d(i32 %x) {
; CHECK-LABEL: @test6d(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i32 @llvm.ctlz.i32(i32 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = trunc i32 [[VAR1]] to i16
; CHECK-NEXT: ret i16 [[VAR2]]
entry:
%0 = tail call i32 @llvm.ctlz.i32(i32 %x, i1 true)
%cast = trunc i32 %0 to i16
%tobool = icmp ne i32 %x, 0
%cond = select i1 %tobool, i16 %cast, i16 32
ret i16 %cond
}
define i64 @select_bug1(i32 %x) {
; CHECK-LABEL: @select_bug1(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i32 @llvm.cttz.i32(i32 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = zext i32 [[VAR1]] to i64
; CHECK-NEXT: ret i64 [[VAR2]]
entry:
%0 = tail call i32 @llvm.cttz.i32(i32 %x, i1 false)
%conv = zext i32 %0 to i64
%tobool = icmp ne i32 %x, 0
%cond = select i1 %tobool, i64 %conv, i64 32
ret i64 %cond
}
define i16 @select_bug2(i32 %x) {
; CHECK-LABEL: @select_bug2(
; CHECK: [[VAR1:%[a-zA-Z0-9]+]] = tail call i32 @llvm.cttz.i32(i32 %x, i1 false)
; CHECK-NEXT: [[VAR2:%[a-zA-Z0-9]+]] = trunc i32 [[VAR1]] to i16
; CHECK-NEXT: ret i16 [[VAR2]]
entry:
%0 = tail call i32 @llvm.cttz.i32(i32 %x, i1 false)
%conv = trunc i32 %0 to i16
%tobool = icmp ne i32 %x, 0
%cond = select i1 %tobool, i16 %conv, i16 32
ret i16 %cond
}
declare i16 @llvm.ctlz.i16(i16, i1)
declare i32 @llvm.ctlz.i32(i32, i1)
declare i64 @llvm.ctlz.i64(i64, i1)
declare i16 @llvm.cttz.i16(i16, i1)
declare i32 @llvm.cttz.i32(i32, i1)
declare i64 @llvm.cttz.i64(i64, i1)