llvm-6502/test/CodeGen/X86/lzcnt-tzcnt.ll
Andrea Di Biagio 8e4a223f7b [X86] Add ISel patterns to improve the selection of TZCNT and LZCNT.
Instructions TZCNT (requires BMI1) and LZCNT (requires LZCNT), always
provide the operand size as output if the input operand is zero.

We can take advantage of this knowledge during instruction selection
stage in order to simplify a few corner case.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209159 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-19 20:38:59 +00:00

448 lines
9.9 KiB
LLVM

; RUN: llc < %s -mtriple=x86_64-pc-linux -mattr=+bmi,+lzcnt | FileCheck %s
; LZCNT and TZCNT will always produce the operand size when the input operand
; is zero. This test is to verify that we efficiently select LZCNT/TZCNT
; based on the fact that the 'icmp+select' sequence is always redundant
; in every function defined below.
define i16 @test1_ctlz(i16 %v) {
%cnt = tail call i16 @llvm.ctlz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 %v, 0
%cond = select i1 %tobool, i16 16, i16 %cnt
ret i16 %cond
}
; CHECK-LABEL: test1_ctlz
; CHECK: lzcnt
; CHECK-NEXT: ret
define i32 @test2_ctlz(i32 %v) {
%cnt = tail call i32 @llvm.ctlz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 %v, 0
%cond = select i1 %tobool, i32 32, i32 %cnt
ret i32 %cond
}
; CHECK-LABEL: test2_ctlz
; CHECK: lzcnt
; CHECK-NEXT: ret
define i64 @test3_ctlz(i64 %v) {
%cnt = tail call i64 @llvm.ctlz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 %v, 0
%cond = select i1 %tobool, i64 64, i64 %cnt
ret i64 %cond
}
; CHECK-LABEL: test3_ctlz
; CHECK: lzcnt
; CHECK-NEXT: ret
define i16 @test4_ctlz(i16 %v) {
%cnt = tail call i16 @llvm.ctlz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 0, %v
%cond = select i1 %tobool, i16 16, i16 %cnt
ret i16 %cond
}
; CHECK-LABEL: test4_ctlz
; CHECK: lzcnt
; CHECK-NEXT: ret
define i32 @test5_ctlz(i32 %v) {
%cnt = tail call i32 @llvm.ctlz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 0, %v
%cond = select i1 %tobool, i32 32, i32 %cnt
ret i32 %cond
}
; CHECK-LABEL: test5_ctlz
; CHECK: lzcnt
; CHECK-NEXT: ret
define i64 @test6_ctlz(i64 %v) {
%cnt = tail call i64 @llvm.ctlz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 0, %v
%cond = select i1 %tobool, i64 64, i64 %cnt
ret i64 %cond
}
; CHECK-LABEL: test6_ctlz
; CHECK: lzcnt
; CHECK-NEXT: ret
define i16 @test7_ctlz(i16 %v) {
%cnt = tail call i16 @llvm.ctlz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 0, %v
%cond = select i1 %tobool, i16 %cnt, i16 16
ret i16 %cond
}
; CHECK-LABEL: test7_ctlz
; CHECK: lzcnt
; CHECK-NEXT: ret
define i32 @test8_ctlz(i32 %v) {
%cnt = tail call i32 @llvm.ctlz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 0, %v
%cond = select i1 %tobool, i32 %cnt, i32 32
ret i32 %cond
}
; CHECK-LABEL: test8_ctlz
; CHECK: lzcnt
; CHECK-NEXT: ret
define i64 @test9_ctlz(i64 %v) {
%cnt = tail call i64 @llvm.ctlz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 0, %v
%cond = select i1 %tobool, i64 %cnt, i64 64
ret i64 %cond
}
; CHECK-LABEL: test9_ctlz
; CHECK: lzcnt
; CHECK-NEXT: ret
define i16 @test10_ctlz(i16* %ptr) {
%v = load i16* %ptr
%cnt = tail call i16 @llvm.ctlz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 %v, 0
%cond = select i1 %tobool, i16 16, i16 %cnt
ret i16 %cond
}
; CHECK-LABEL: test10_ctlz
; CHECK-NOT: movw
; CHECK: lzcnt
; CHECK-NEXT: ret
define i32 @test11_ctlz(i32* %ptr) {
%v = load i32* %ptr
%cnt = tail call i32 @llvm.ctlz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 %v, 0
%cond = select i1 %tobool, i32 32, i32 %cnt
ret i32 %cond
}
; CHECK-LABEL: test11_ctlz
; CHECK-NOT: movd
; CHECK: lzcnt
; CHECK-NEXT: ret
define i64 @test12_ctlz(i64* %ptr) {
%v = load i64* %ptr
%cnt = tail call i64 @llvm.ctlz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 %v, 0
%cond = select i1 %tobool, i64 64, i64 %cnt
ret i64 %cond
}
; CHECK-LABEL: test12_ctlz
; CHECK-NOT: movq
; CHECK: lzcnt
; CHECK-NEXT: ret
define i16 @test13_ctlz(i16* %ptr) {
%v = load i16* %ptr
%cnt = tail call i16 @llvm.ctlz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 0, %v
%cond = select i1 %tobool, i16 16, i16 %cnt
ret i16 %cond
}
; CHECK-LABEL: test13_ctlz
; CHECK-NOT: movw
; CHECK: lzcnt
; CHECK-NEXT: ret
define i32 @test14_ctlz(i32* %ptr) {
%v = load i32* %ptr
%cnt = tail call i32 @llvm.ctlz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 0, %v
%cond = select i1 %tobool, i32 32, i32 %cnt
ret i32 %cond
}
; CHECK-LABEL: test14_ctlz
; CHECK-NOT: movd
; CHECK: lzcnt
; CHECK-NEXT: ret
define i64 @test15_ctlz(i64* %ptr) {
%v = load i64* %ptr
%cnt = tail call i64 @llvm.ctlz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 0, %v
%cond = select i1 %tobool, i64 64, i64 %cnt
ret i64 %cond
}
; CHECK-LABEL: test15_ctlz
; CHECK-NOT: movq
; CHECK: lzcnt
; CHECK-NEXT: ret
define i16 @test16_ctlz(i16* %ptr) {
%v = load i16* %ptr
%cnt = tail call i16 @llvm.ctlz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 0, %v
%cond = select i1 %tobool, i16 %cnt, i16 16
ret i16 %cond
}
; CHECK-LABEL: test16_ctlz
; CHECK-NOT: movw
; CHECK: lzcnt
; CHECK-NEXT: ret
define i32 @test17_ctlz(i32* %ptr) {
%v = load i32* %ptr
%cnt = tail call i32 @llvm.ctlz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 0, %v
%cond = select i1 %tobool, i32 %cnt, i32 32
ret i32 %cond
}
; CHECK-LABEL: test17_ctlz
; CHECK-NOT: movd
; CHECK: lzcnt
; CHECK-NEXT: ret
define i64 @test18_ctlz(i64* %ptr) {
%v = load i64* %ptr
%cnt = tail call i64 @llvm.ctlz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 0, %v
%cond = select i1 %tobool, i64 %cnt, i64 64
ret i64 %cond
}
; CHECK-LABEL: test18_ctlz
; CHECK-NOT: movq
; CHECK: lzcnt
; CHECK-NEXT: ret
define i16 @test1_cttz(i16 %v) {
%cnt = tail call i16 @llvm.cttz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 %v, 0
%cond = select i1 %tobool, i16 16, i16 %cnt
ret i16 %cond
}
; CHECK-LABEL: test1_cttz
; CHECK: tzcnt
; CHECK-NEXT: ret
define i32 @test2_cttz(i32 %v) {
%cnt = tail call i32 @llvm.cttz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 %v, 0
%cond = select i1 %tobool, i32 32, i32 %cnt
ret i32 %cond
}
; CHECK-LABEL: test2_cttz
; CHECK: tzcnt
; CHECK-NEXT: ret
define i64 @test3_cttz(i64 %v) {
%cnt = tail call i64 @llvm.cttz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 %v, 0
%cond = select i1 %tobool, i64 64, i64 %cnt
ret i64 %cond
}
; CHECK-LABEL: test3_cttz
; CHECK: tzcnt
; CHECK-NEXT: ret
define i16 @test4_cttz(i16 %v) {
%cnt = tail call i16 @llvm.cttz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 0, %v
%cond = select i1 %tobool, i16 16, i16 %cnt
ret i16 %cond
}
; CHECK-LABEL: test4_cttz
; CHECK: tzcnt
; CHECK-NEXT: ret
define i32 @test5_cttz(i32 %v) {
%cnt = tail call i32 @llvm.cttz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 0, %v
%cond = select i1 %tobool, i32 32, i32 %cnt
ret i32 %cond
}
; CHECK-LABEL: test5_cttz
; CHECK: tzcnt
; CHECK-NEXT: ret
define i64 @test6_cttz(i64 %v) {
%cnt = tail call i64 @llvm.cttz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 0, %v
%cond = select i1 %tobool, i64 64, i64 %cnt
ret i64 %cond
}
; CHECK-LABEL: test6_cttz
; CHECK: tzcnt
; CHECK-NEXT: ret
define i16 @test7_cttz(i16 %v) {
%cnt = tail call i16 @llvm.cttz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 0, %v
%cond = select i1 %tobool, i16 %cnt, i16 16
ret i16 %cond
}
; CHECK-LABEL: test7_cttz
; CHECK: tzcnt
; CHECK-NEXT: ret
define i32 @test8_cttz(i32 %v) {
%cnt = tail call i32 @llvm.cttz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 0, %v
%cond = select i1 %tobool, i32 %cnt, i32 32
ret i32 %cond
}
; CHECK-LABEL: test8_cttz
; CHECK: tzcnt
; CHECK-NEXT: ret
define i64 @test9_cttz(i64 %v) {
%cnt = tail call i64 @llvm.cttz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 0, %v
%cond = select i1 %tobool, i64 %cnt, i64 64
ret i64 %cond
}
; CHECK-LABEL: test9_cttz
; CHECK: tzcnt
; CHECK-NEXT: ret
define i16 @test10_cttz(i16* %ptr) {
%v = load i16* %ptr
%cnt = tail call i16 @llvm.cttz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 %v, 0
%cond = select i1 %tobool, i16 16, i16 %cnt
ret i16 %cond
}
; CHECK-LABEL: test10_cttz
; CHECK-NOT: movw
; CHECK: tzcnt
; CHECK-NEXT: ret
define i32 @test11_cttz(i32* %ptr) {
%v = load i32* %ptr
%cnt = tail call i32 @llvm.cttz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 %v, 0
%cond = select i1 %tobool, i32 32, i32 %cnt
ret i32 %cond
}
; CHECK-LABEL: test11_cttz
; CHECK-NOT: movd
; CHECK: tzcnt
; CHECK-NEXT: ret
define i64 @test12_cttz(i64* %ptr) {
%v = load i64* %ptr
%cnt = tail call i64 @llvm.cttz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 %v, 0
%cond = select i1 %tobool, i64 64, i64 %cnt
ret i64 %cond
}
; CHECK-LABEL: test12_cttz
; CHECK-NOT: movq
; CHECK: tzcnt
; CHECK-NEXT: ret
define i16 @test13_cttz(i16* %ptr) {
%v = load i16* %ptr
%cnt = tail call i16 @llvm.cttz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 0, %v
%cond = select i1 %tobool, i16 16, i16 %cnt
ret i16 %cond
}
; CHECK-LABEL: test13_cttz
; CHECK-NOT: movw
; CHECK: tzcnt
; CHECK-NEXT: ret
define i32 @test14_cttz(i32* %ptr) {
%v = load i32* %ptr
%cnt = tail call i32 @llvm.cttz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 0, %v
%cond = select i1 %tobool, i32 32, i32 %cnt
ret i32 %cond
}
; CHECK-LABEL: test14_cttz
; CHECK-NOT: movd
; CHECK: tzcnt
; CHECK-NEXT: ret
define i64 @test15_cttz(i64* %ptr) {
%v = load i64* %ptr
%cnt = tail call i64 @llvm.cttz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 0, %v
%cond = select i1 %tobool, i64 64, i64 %cnt
ret i64 %cond
}
; CHECK-LABEL: test15_cttz
; CHECK-NOT: movq
; CHECK: tzcnt
; CHECK-NEXT: ret
define i16 @test16_cttz(i16* %ptr) {
%v = load i16* %ptr
%cnt = tail call i16 @llvm.cttz.i16(i16 %v, i1 true)
%tobool = icmp eq i16 0, %v
%cond = select i1 %tobool, i16 %cnt, i16 16
ret i16 %cond
}
; CHECK-LABEL: test16_cttz
; CHECK-NOT: movw
; CHECK: tzcnt
; CHECK-NEXT: ret
define i32 @test17_cttz(i32* %ptr) {
%v = load i32* %ptr
%cnt = tail call i32 @llvm.cttz.i32(i32 %v, i1 true)
%tobool = icmp eq i32 0, %v
%cond = select i1 %tobool, i32 %cnt, i32 32
ret i32 %cond
}
; CHECK-LABEL: test17_cttz
; CHECK-NOT: movd
; CHECK: tzcnt
; CHECK-NEXT: ret
define i64 @test18_cttz(i64* %ptr) {
%v = load i64* %ptr
%cnt = tail call i64 @llvm.cttz.i64(i64 %v, i1 true)
%tobool = icmp eq i64 0, %v
%cond = select i1 %tobool, i64 %cnt, i64 64
ret i64 %cond
}
; CHECK-LABEL: test18_cttz
; CHECK-NOT: movq
; CHECK: tzcnt
; CHECK-NEXT: ret
declare i64 @llvm.cttz.i64(i64, i1)
declare i32 @llvm.cttz.i32(i32, i1)
declare i16 @llvm.cttz.i16(i16, i1)
declare i64 @llvm.ctlz.i64(i64, i1)
declare i32 @llvm.ctlz.i32(i32, i1)
declare i16 @llvm.ctlz.i16(i16, i1)