; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -instsimplify -S | FileCheck %s define i32 @zero_dividend(i32 %A) { ; CHECK-LABEL: @zero_dividend( ; CHECK-NEXT: ret i32 0 ; %B = sdiv i32 0, %A ret i32 %B } define <2 x i32> @zero_dividend_vector(<2 x i32> %A) { ; CHECK-LABEL: @zero_dividend_vector( ; CHECK-NEXT: ret <2 x i32> zeroinitializer ; %B = udiv <2 x i32> zeroinitializer, %A ret <2 x i32> %B } define <2 x i32> @zero_dividend_vector_undef_elt(<2 x i32> %A) { ; CHECK-LABEL: @zero_dividend_vector_undef_elt( ; CHECK-NEXT: ret <2 x i32> zeroinitializer ; %B = sdiv <2 x i32> , %A ret <2 x i32> %B } ; Division-by-zero is undef. UB in any vector lane means the whole op is undef. define <2 x i8> @sdiv_zero_elt_vec_constfold(<2 x i8> %x) { ; CHECK-LABEL: @sdiv_zero_elt_vec_constfold( ; CHECK-NEXT: ret <2 x i8> undef ; %div = sdiv <2 x i8> , ret <2 x i8> %div } define <2 x i8> @udiv_zero_elt_vec_constfold(<2 x i8> %x) { ; CHECK-LABEL: @udiv_zero_elt_vec_constfold( ; CHECK-NEXT: ret <2 x i8> undef ; %div = udiv <2 x i8> , ret <2 x i8> %div } define <2 x i8> @sdiv_zero_elt_vec(<2 x i8> %x) { ; CHECK-LABEL: @sdiv_zero_elt_vec( ; CHECK-NEXT: ret <2 x i8> undef ; %div = sdiv <2 x i8> %x, ret <2 x i8> %div } define <2 x i8> @udiv_zero_elt_vec(<2 x i8> %x) { ; CHECK-LABEL: @udiv_zero_elt_vec( ; CHECK-NEXT: ret <2 x i8> undef ; %div = udiv <2 x i8> %x, ret <2 x i8> %div } define <2 x i8> @sdiv_undef_elt_vec(<2 x i8> %x) { ; CHECK-LABEL: @sdiv_undef_elt_vec( ; CHECK-NEXT: ret <2 x i8> undef ; %div = sdiv <2 x i8> %x, ret <2 x i8> %div } define <2 x i8> @udiv_undef_elt_vec(<2 x i8> %x) { ; CHECK-LABEL: @udiv_undef_elt_vec( ; CHECK-NEXT: ret <2 x i8> undef ; %div = udiv <2 x i8> %x, ret <2 x i8> %div } ; Division-by-zero is undef. UB in any vector lane means the whole op is undef. ; Thus, we can simplify this: if any element of 'y' is 0, we can do anything. ; Therefore, assume that all elements of 'y' must be 1. define <2 x i1> @sdiv_bool_vec(<2 x i1> %x, <2 x i1> %y) { ; CHECK-LABEL: @sdiv_bool_vec( ; CHECK-NEXT: ret <2 x i1> [[X:%.*]] ; %div = sdiv <2 x i1> %x, %y ret <2 x i1> %div } define <2 x i1> @udiv_bool_vec(<2 x i1> %x, <2 x i1> %y) { ; CHECK-LABEL: @udiv_bool_vec( ; CHECK-NEXT: ret <2 x i1> [[X:%.*]] ; %div = udiv <2 x i1> %x, %y ret <2 x i1> %div } define i32 @zext_bool_udiv_divisor(i1 %x, i32 %y) { ; CHECK-LABEL: @zext_bool_udiv_divisor( ; CHECK-NEXT: ret i32 [[Y:%.*]] ; %ext = zext i1 %x to i32 %r = udiv i32 %y, %ext ret i32 %r } define <2 x i32> @zext_bool_sdiv_divisor_vec(<2 x i1> %x, <2 x i32> %y) { ; CHECK-LABEL: @zext_bool_sdiv_divisor_vec( ; CHECK-NEXT: ret <2 x i32> [[Y:%.*]] ; %ext = zext <2 x i1> %x to <2 x i32> %r = sdiv <2 x i32> %y, %ext ret <2 x i32> %r } define i32 @udiv_dividend_known_smaller_than_constant_divisor(i32 %x) { ; CHECK-LABEL: @udiv_dividend_known_smaller_than_constant_divisor( ; CHECK-NEXT: ret i32 0 ; %and = and i32 %x, 250 %div = udiv i32 %and, 251 ret i32 %div } define i32 @not_udiv_dividend_known_smaller_than_constant_divisor(i32 %x) { ; CHECK-LABEL: @not_udiv_dividend_known_smaller_than_constant_divisor( ; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], 251 ; CHECK-NEXT: [[DIV:%.*]] = udiv i32 [[AND]], 251 ; CHECK-NEXT: ret i32 [[DIV]] ; %and = and i32 %x, 251 %div = udiv i32 %and, 251 ret i32 %div } define i32 @udiv_constant_dividend_known_smaller_than_divisor(i32 %x) { ; CHECK-LABEL: @udiv_constant_dividend_known_smaller_than_divisor( ; CHECK-NEXT: ret i32 0 ; %or = or i32 %x, 251 %div = udiv i32 250, %or ret i32 %div } define i32 @not_udiv_constant_dividend_known_smaller_than_divisor(i32 %x) { ; CHECK-LABEL: @not_udiv_constant_dividend_known_smaller_than_divisor( ; CHECK-NEXT: [[OR:%.*]] = or i32 [[X:%.*]], 251 ; CHECK-NEXT: [[DIV:%.*]] = udiv i32 251, [[OR]] ; CHECK-NEXT: ret i32 [[DIV]] ; %or = or i32 %x, 251 %div = udiv i32 251, %or ret i32 %div } ; This would require computing known bits on both x and y. Is it worth doing? define i32 @udiv_dividend_known_smaller_than_divisor(i32 %x, i32 %y) { ; CHECK-LABEL: @udiv_dividend_known_smaller_than_divisor( ; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], 250 ; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], 251 ; CHECK-NEXT: [[DIV:%.*]] = udiv i32 [[AND]], [[OR]] ; CHECK-NEXT: ret i32 [[DIV]] ; %and = and i32 %x, 250 %or = or i32 %y, 251 %div = udiv i32 %and, %or ret i32 %div } define i32 @not_udiv_dividend_known_smaller_than_divisor(i32 %x, i32 %y) { ; CHECK-LABEL: @not_udiv_dividend_known_smaller_than_divisor( ; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], 251 ; CHECK-NEXT: [[OR:%.*]] = or i32 [[Y:%.*]], 251 ; CHECK-NEXT: [[DIV:%.*]] = udiv i32 [[AND]], [[OR]] ; CHECK-NEXT: ret i32 [[DIV]] ; %and = and i32 %x, 251 %or = or i32 %y, 251 %div = udiv i32 %and, %or ret i32 %div } declare i32 @external() define i32 @div1() { ; CHECK-LABEL: @div1( ; CHECK-NEXT: [[CALL:%.*]] = call i32 @external(), !range !0 ; CHECK-NEXT: ret i32 0 ; %call = call i32 @external(), !range !0 %urem = udiv i32 %call, 3 ret i32 %urem } !0 = !{i32 0, i32 3}