1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
|
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-unknown-unknown | FileCheck %s
define i64 @foo(i64 %x, i64 %y) {
; CHECK-LABEL: foo:
; CHECK: # %bb.0:
; CHECK-NEXT: bsrq %rdi, %rax
; CHECK-NEXT: xorq $64, %rax
; CHECK-NEXT: bsrq %rsi, %rcx
; CHECK-NEXT: cmoveq %rax, %rcx
; CHECK-NEXT: movl $63, %eax
; CHECK-NEXT: subq %rcx, %rax
; CHECK-NEXT: retq
%1 = tail call i64 @llvm.ctlz.i64(i64 %x, i1 true)
%2 = xor i64 %1, 127
%3 = tail call i64 @llvm.ctlz.i64(i64 %y, i1 true)
%4 = xor i64 %3, 63
%5 = icmp eq i64 %y, 0
%6 = select i1 %5, i64 %2, i64 %4
%7 = sub nsw i64 63, %6
ret i64 %7
}
declare i64 @llvm.ctlz.i64(i64, i1)
|
