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; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=-bmi2,-lzcnt | FileCheck %s --check-prefix=NOBMI
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+bmi2,+lzcnt | FileCheck %s --check-prefix=BMI
; Check the assembly sequence generated for std::bit_ceil.
; std::bit_ceil<uint32_t>(x)
define i32 @bit_ceil_i32(i32 %x) {
; NOBMI-LABEL: bit_ceil_i32:
; NOBMI: # %bb.0:
; NOBMI-NEXT: # kill: def $edi killed $edi def $rdi
; NOBMI-NEXT: leal -1(%rdi), %eax
; NOBMI-NEXT: movl $63, %ecx
; NOBMI-NEXT: bsrl %eax, %ecx
; NOBMI-NEXT: xorl $31, %ecx
; NOBMI-NEXT: negb %cl
; NOBMI-NEXT: movl $1, %edx
; NOBMI-NEXT: movl $1, %eax
; NOBMI-NEXT: # kill: def $cl killed $cl killed $ecx
; NOBMI-NEXT: shll %cl, %eax
; NOBMI-NEXT: cmpl $2, %edi
; NOBMI-NEXT: cmovbl %edx, %eax
; NOBMI-NEXT: retq
;
; BMI-LABEL: bit_ceil_i32:
; BMI: # %bb.0:
; BMI-NEXT: # kill: def $edi killed $edi def $rdi
; BMI-NEXT: leal -1(%rdi), %eax
; BMI-NEXT: lzcntl %eax, %eax
; BMI-NEXT: negb %al
; BMI-NEXT: movl $1, %ecx
; BMI-NEXT: shlxl %eax, %ecx, %eax
; BMI-NEXT: cmpl $2, %edi
; BMI-NEXT: cmovbl %ecx, %eax
; BMI-NEXT: retq
%dec = add i32 %x, -1
%lz = tail call i32 @llvm.ctlz.i32(i32 %dec, i1 false)
%cnt = sub i32 32, %lz
%res = shl i32 1, %cnt
%ugt = icmp ugt i32 %x, 1
%sel = select i1 %ugt, i32 %res, i32 1
ret i32 %sel
}
; std::bit_ceil<uint32_t>(x + 1)
define i32 @bit_ceil_i32_plus1(i32 noundef %x) {
; NOBMI-LABEL: bit_ceil_i32_plus1:
; NOBMI: # %bb.0: # %entry
; NOBMI-NEXT: movl $63, %ecx
; NOBMI-NEXT: bsrl %edi, %ecx
; NOBMI-NEXT: xorl $31, %ecx
; NOBMI-NEXT: negb %cl
; NOBMI-NEXT: movl $1, %edx
; NOBMI-NEXT: movl $1, %eax
; NOBMI-NEXT: # kill: def $cl killed $cl killed $ecx
; NOBMI-NEXT: shll %cl, %eax
; NOBMI-NEXT: decl %edi
; NOBMI-NEXT: cmpl $-2, %edi
; NOBMI-NEXT: cmovael %edx, %eax
; NOBMI-NEXT: retq
;
; BMI-LABEL: bit_ceil_i32_plus1:
; BMI: # %bb.0: # %entry
; BMI-NEXT: lzcntl %edi, %eax
; BMI-NEXT: negb %al
; BMI-NEXT: movl $1, %ecx
; BMI-NEXT: shlxl %eax, %ecx, %eax
; BMI-NEXT: decl %edi
; BMI-NEXT: cmpl $-2, %edi
; BMI-NEXT: cmovael %ecx, %eax
; BMI-NEXT: retq
entry:
%ctlz = tail call i32 @llvm.ctlz.i32(i32 %x, i1 false)
%cnt = sub i32 32, %ctlz
%shl = shl i32 1, %cnt
%dec = add i32 %x, -1
%ult = icmp ult i32 %dec, -2
%sel = select i1 %ult, i32 %shl, i32 1
ret i32 %sel
}
; std::bit_ceil<uint64_t>(x)
define i64 @bit_ceil_i64(i64 %x) {
; NOBMI-LABEL: bit_ceil_i64:
; NOBMI: # %bb.0:
; NOBMI-NEXT: leaq -1(%rdi), %rax
; NOBMI-NEXT: movl $127, %ecx
; NOBMI-NEXT: bsrq %rax, %rcx
; NOBMI-NEXT: xorl $63, %ecx
; NOBMI-NEXT: negb %cl
; NOBMI-NEXT: movl $1, %edx
; NOBMI-NEXT: movl $1, %eax
; NOBMI-NEXT: # kill: def $cl killed $cl killed $rcx
; NOBMI-NEXT: shlq %cl, %rax
; NOBMI-NEXT: cmpq $2, %rdi
; NOBMI-NEXT: cmovbq %rdx, %rax
; NOBMI-NEXT: retq
;
; BMI-LABEL: bit_ceil_i64:
; BMI: # %bb.0:
; BMI-NEXT: leaq -1(%rdi), %rax
; BMI-NEXT: lzcntq %rax, %rax
; BMI-NEXT: negb %al
; BMI-NEXT: movl $1, %ecx
; BMI-NEXT: shlxq %rax, %rcx, %rax
; BMI-NEXT: cmpq $2, %rdi
; BMI-NEXT: cmovbq %rcx, %rax
; BMI-NEXT: retq
%dec = add i64 %x, -1
%lz = tail call i64 @llvm.ctlz.i64(i64 %dec, i1 false)
%cnt = sub i64 64, %lz
%res = shl i64 1, %cnt
%ugt = icmp ugt i64 %x, 1
%sel = select i1 %ugt, i64 %res, i64 1
ret i64 %sel
}
; std::bit_ceil<uint64_t>(x + 1)
define i64 @bit_ceil_i64_plus1(i64 noundef %x) {
; NOBMI-LABEL: bit_ceil_i64_plus1:
; NOBMI: # %bb.0: # %entry
; NOBMI-NEXT: movl $127, %ecx
; NOBMI-NEXT: bsrq %rdi, %rcx
; NOBMI-NEXT: xorl $63, %ecx
; NOBMI-NEXT: negb %cl
; NOBMI-NEXT: movl $1, %edx
; NOBMI-NEXT: movl $1, %eax
; NOBMI-NEXT: # kill: def $cl killed $cl killed $rcx
; NOBMI-NEXT: shlq %cl, %rax
; NOBMI-NEXT: decq %rdi
; NOBMI-NEXT: cmpq $-2, %rdi
; NOBMI-NEXT: cmovaeq %rdx, %rax
; NOBMI-NEXT: retq
;
; BMI-LABEL: bit_ceil_i64_plus1:
; BMI: # %bb.0: # %entry
; BMI-NEXT: lzcntq %rdi, %rax
; BMI-NEXT: negb %al
; BMI-NEXT: movl $1, %ecx
; BMI-NEXT: shlxq %rax, %rcx, %rax
; BMI-NEXT: decq %rdi
; BMI-NEXT: cmpq $-2, %rdi
; BMI-NEXT: cmovaeq %rcx, %rax
; BMI-NEXT: retq
entry:
%ctlz = tail call i64 @llvm.ctlz.i64(i64 %x, i1 false)
%cnt = sub i64 64, %ctlz
%shl = shl i64 1, %cnt
%dec = add i64 %x, -1
%ult = icmp ult i64 %dec, -2
%sel = select i1 %ult, i64 %shl, i64 1
ret i64 %sel
}
declare i32 @llvm.ctlz.i32(i32, i1 immarg)
declare i64 @llvm.ctlz.i64(i64, i1 immarg)
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