; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: llc < %s -mtriple=x86_64-unknown-unknown | FileCheck %s ; The easy case: a constant power-of-2 divisor. define i64 @const_pow_2(i64 %x) { ; CHECK-LABEL: const_pow_2: ; CHECK: # BB#0: ; CHECK-NEXT: andl $31, %edi ; CHECK-NEXT: movq %rdi, %rax ; CHECK-NEXT: retq ; %urem = urem i64 %x, 32 ret i64 %urem } ; A left-shifted power-of-2 divisor. Use a weird type for wider coverage. define i25 @shift_left_pow_2(i25 %x, i25 %y) { ; CHECK-LABEL: shift_left_pow_2: ; CHECK: # BB#0: ; CHECK-NEXT: movl $1, %eax ; CHECK-NEXT: movl %esi, %ecx ; CHECK-NEXT: shll %cl, %eax ; CHECK-NEXT: addl $33554431, %eax # imm = 0x1FFFFFF ; CHECK-NEXT: andl %edi, %eax ; CHECK-NEXT: retq ; %shl = shl i25 1, %y %urem = urem i25 %x, %shl ret i25 %urem } ; FIXME: A logically right-shifted sign bit is a power-of-2 or UB. define i16 @shift_right_pow_2(i16 %x, i16 %y) { ; CHECK-LABEL: shift_right_pow_2: ; CHECK: # BB#0: ; CHECK-NEXT: movl $32768, %r8d # imm = 0x8000 ; CHECK-NEXT: movl %esi, %ecx ; CHECK-NEXT: shrl %cl, %r8d ; CHECK-NEXT: xorl %edx, %edx ; CHECK-NEXT: movl %edi, %eax ; CHECK-NEXT: divw %r8w ; CHECK-NEXT: movl %edx, %eax ; CHECK-NEXT: retq ; %shr = lshr i16 -32768, %y %urem = urem i16 %x, %shr ret i16 %urem } ; FIXME: A zero divisor would be UB, so this could be reduced to an 'and' with 3. define i8 @and_pow_2(i8 %x, i8 %y) { ; CHECK-LABEL: and_pow_2: ; CHECK: # BB#0: ; CHECK-NEXT: andb $4, %sil ; CHECK-NEXT: movzbl %dil, %eax ; CHECK-NEXT: # kill: %EAX<def> %EAX<kill> %AX<def> ; CHECK-NEXT: divb %sil ; CHECK-NEXT: movzbl %ah, %eax # NOREX ; CHECK-NEXT: # kill: %AL<def> %AL<kill> %EAX<kill> ; CHECK-NEXT: retq ; %and = and i8 %y, 4 %urem = urem i8 %x, %and ret i8 %urem } ; A vector splat constant divisor should get the same treatment as a scalar. define <4 x i32> @vec_const_pow_2(<4 x i32> %x) { ; CHECK-LABEL: vec_const_pow_2: ; CHECK: # BB#0: ; CHECK-NEXT: andps {{.*}}(%rip), %xmm0 ; CHECK-NEXT: retq ; %urem = urem <4 x i32> %x, <i32 16, i32 16, i32 16, i32 16> ret <4 x i32> %urem }