; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=aggressive-instcombine -S | FileCheck %s define i16 @lshr_15(i16 %x) { ; CHECK-LABEL: @lshr_15( ; CHECK-NEXT: [[LSHR:%.*]] = lshr i16 [[X:%.*]], 15 ; CHECK-NEXT: ret i16 [[LSHR]] ; %zext = zext i16 %x to i32 %lshr = lshr i32 %zext, 15 %trunc = trunc i32 %lshr to i16 ret i16 %trunc } ; Negative test define i16 @lshr_16(i16 %x) { ; CHECK-LABEL: @lshr_16( ; CHECK-NEXT: [[ZEXT:%.*]] = zext i16 [[X:%.*]] to i32 ; CHECK-NEXT: [[LSHR:%.*]] = lshr i32 [[ZEXT]], 16 ; CHECK-NEXT: [[TRUNC:%.*]] = trunc i32 [[LSHR]] to i16 ; CHECK-NEXT: ret i16 [[TRUNC]] ; %zext = zext i16 %x to i32 %lshr = lshr i32 %zext, 16 %trunc = trunc i32 %lshr to i16 ret i16 %trunc } ; Negative test define i16 @lshr_var_shift_amount(i8 %x, i8 %amt) { ; CHECK-LABEL: @lshr_var_shift_amount( ; CHECK-NEXT: [[Z:%.*]] = zext i8 [[X:%.*]] to i32 ; CHECK-NEXT: [[ZA:%.*]] = zext i8 [[AMT:%.*]] to i32 ; CHECK-NEXT: [[S:%.*]] = lshr i32 [[Z]], [[ZA]] ; CHECK-NEXT: [[A:%.*]] = add i32 [[S]], [[Z]] ; CHECK-NEXT: [[S2:%.*]] = lshr i32 [[A]], 2 ; CHECK-NEXT: [[T:%.*]] = trunc i32 [[S2]] to i16 ; CHECK-NEXT: ret i16 [[T]] ; %z = zext i8 %x to i32 %za = zext i8 %amt to i32 %s = lshr i32 %z, %za %a = add i32 %s, %z %s2 = lshr i32 %a, 2 %t = trunc i32 %s2 to i16 ret i16 %t } define i16 @lshr_var_bounded_shift_amount(i8 %x, i8 %amt) { ; CHECK-LABEL: @lshr_var_bounded_shift_amount( ; CHECK-NEXT: [[Z:%.*]] = zext i8 [[X:%.*]] to i16 ; CHECK-NEXT: [[ZA:%.*]] = zext i8 [[AMT:%.*]] to i16 ; CHECK-NEXT: [[ZA2:%.*]] = and i16 [[ZA]], 15 ; CHECK-NEXT: [[S:%.*]] = lshr i16 [[Z]], [[ZA2]] ; CHECK-NEXT: [[A:%.*]] = add i16 [[S]], [[Z]] ; CHECK-NEXT: [[S2:%.*]] = lshr i16 [[A]], 2 ; CHECK-NEXT: ret i16 [[S2]] ; %z = zext i8 %x to i32 %za = zext i8 %amt to i32 %za2 = and i32 %za, 15 %s = lshr i32 %z, %za2 %a = add i32 %s, %z %s2 = lshr i32 %a, 2 %t = trunc i32 %s2 to i16 ret i16 %t } ; Negative test define i32 @lshr_check_no_overflow(i32 %x, i16 %amt) { ; CHECK-LABEL: @lshr_check_no_overflow( ; CHECK-NEXT: [[ZEXT:%.*]] = zext i32 [[X:%.*]] to i64 ; CHECK-NEXT: [[SEXT:%.*]] = sext i16 [[AMT:%.*]] to i64 ; CHECK-NEXT: [[AND:%.*]] = and i64 [[SEXT]], 4294967295 ; CHECK-NEXT: [[SHL:%.*]] = lshr i64 [[ZEXT]], [[AND]] ; CHECK-NEXT: [[TRUNC:%.*]] = trunc i64 [[SHL]] to i32 ; CHECK-NEXT: ret i32 [[TRUNC]] ; %zext = zext i32 %x to i64 %sext = sext i16 %amt to i64 %and = and i64 %sext, 4294967295 %shl = lshr i64 %zext, %and %trunc = trunc i64 %shl to i32 ret i32 %trunc } define void @lshr_big_dag(ptr %a, i8 %b, i8 %c) { ; CHECK-LABEL: @lshr_big_dag( ; CHECK-NEXT: [[ZEXT1:%.*]] = zext i8 [[B:%.*]] to i16 ; CHECK-NEXT: [[ZEXT2:%.*]] = zext i8 [[C:%.*]] to i16 ; CHECK-NEXT: [[ADD1:%.*]] = add i16 [[ZEXT1]], [[ZEXT2]] ; CHECK-NEXT: [[SFT1:%.*]] = and i16 [[ADD1]], 15 ; CHECK-NEXT: [[SHR1:%.*]] = lshr i16 [[ADD1]], [[SFT1]] ; CHECK-NEXT: [[ADD2:%.*]] = add i16 [[ADD1]], [[SHR1]] ; CHECK-NEXT: [[SFT2:%.*]] = and i16 [[ADD2]], 7 ; CHECK-NEXT: [[SHR2:%.*]] = lshr i16 [[ADD2]], [[SFT2]] ; CHECK-NEXT: store i16 [[SHR2]], ptr [[A:%.*]], align 2 ; CHECK-NEXT: ret void ; %zext1 = zext i8 %b to i32 %zext2 = zext i8 %c to i32 %add1 = add i32 %zext1, %zext2 %sft1 = and i32 %add1, 15 %shr1 = lshr i32 %add1, %sft1 %add2 = add i32 %add1, %shr1 %sft2 = and i32 %add2, 7 %shr2 = lshr i32 %add2, %sft2 %trunc = trunc i32 %shr2 to i16 store i16 %trunc, ptr %a, align 2 ret void } ; Negative test define i8 @lshr_check_not_i8_trunc(i16 %x) { ; CHECK-LABEL: @lshr_check_not_i8_trunc( ; CHECK-NEXT: [[LSHR:%.*]] = lshr i16 [[X:%.*]], 1 ; CHECK-NEXT: [[ZEXT2:%.*]] = zext i16 [[LSHR]] to i32 ; CHECK-NEXT: [[LSHR2:%.*]] = lshr i32 [[ZEXT2]], 2 ; CHECK-NEXT: [[TRUNC:%.*]] = trunc i32 [[LSHR2]] to i8 ; CHECK-NEXT: ret i8 [[TRUNC]] ; %lshr = lshr i16 %x, 1 %zext2 = zext i16 %lshr to i32 %lshr2 = lshr i32 %zext2, 2 %trunc = trunc i32 %lshr2 to i8 ret i8 %trunc } define <2 x i16> @lshr_vector(<2 x i8> %x) { ; CHECK-LABEL: @lshr_vector( ; CHECK-NEXT: [[Z:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i16> ; CHECK-NEXT: [[ZA:%.*]] = and <2 x i16> [[Z]], <i16 7, i16 8> ; CHECK-NEXT: [[S:%.*]] = lshr <2 x i16> [[Z]], [[ZA]] ; CHECK-NEXT: [[A:%.*]] = add <2 x i16> [[S]], [[Z]] ; CHECK-NEXT: [[S2:%.*]] = lshr <2 x i16> [[A]], <i16 4, i16 5> ; CHECK-NEXT: ret <2 x i16> [[S2]] ; %z = zext <2 x i8> %x to <2 x i32> %za = and <2 x i32> %z, <i32 7, i32 8> %s = lshr <2 x i32> %z, %za %a = add <2 x i32> %s, %z %s2 = lshr <2 x i32> %a, <i32 4, i32 5> %t = trunc <2 x i32> %s2 to <2 x i16> ret <2 x i16> %t } ; Negative test - can only fold to <2 x i16>, requiring new vector type define <2 x i8> @lshr_vector_no_new_vector_type(<2 x i8> %x) { ; CHECK-LABEL: @lshr_vector_no_new_vector_type( ; CHECK-NEXT: [[Z:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32> ; CHECK-NEXT: [[ZA:%.*]] = and <2 x i32> [[Z]], <i32 7, i32 8> ; CHECK-NEXT: [[S:%.*]] = lshr <2 x i32> [[Z]], [[ZA]] ; CHECK-NEXT: [[A:%.*]] = add <2 x i32> [[S]], [[Z]] ; CHECK-NEXT: [[S2:%.*]] = lshr <2 x i32> [[A]], <i32 4, i32 5> ; CHECK-NEXT: [[T:%.*]] = trunc <2 x i32> [[S2]] to <2 x i8> ; CHECK-NEXT: ret <2 x i8> [[T]] ; %z = zext <2 x i8> %x to <2 x i32> %za = and <2 x i32> %z, <i32 7, i32 8> %s = lshr <2 x i32> %z, %za %a = add <2 x i32> %s, %z %s2 = lshr <2 x i32> %a, <i32 4, i32 5> %t = trunc <2 x i32> %s2 to <2 x i8> ret <2 x i8> %t } ; Negative test define <2 x i16> @lshr_vector_large_shift_amount(<2 x i8> %x) { ; CHECK-LABEL: @lshr_vector_large_shift_amount( ; CHECK-NEXT: [[Z:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i32> ; CHECK-NEXT: [[ZA:%.*]] = and <2 x i32> [[Z]], <i32 7, i32 8> ; CHECK-NEXT: [[S:%.*]] = lshr <2 x i32> [[Z]], [[ZA]] ; CHECK-NEXT: [[A:%.*]] = add <2 x i32> [[S]], [[Z]] ; CHECK-NEXT: [[S2:%.*]] = lshr <2 x i32> [[A]], <i32 16, i32 5> ; CHECK-NEXT: [[T:%.*]] = trunc <2 x i32> [[S2]] to <2 x i16> ; CHECK-NEXT: ret <2 x i16> [[T]] ; %z = zext <2 x i8> %x to <2 x i32> %za = and <2 x i32> %z, <i32 7, i32 8> %s = lshr <2 x i32> %z, %za %a = add <2 x i32> %s, %z %s2 = lshr <2 x i32> %a, <i32 16, i32 5> %t = trunc <2 x i32> %s2 to <2 x i16> ret <2 x i16> %t } define i16 @lshr_exact(i16 %x) { ; CHECK-LABEL: @lshr_exact( ; CHECK-NEXT: [[LSHR:%.*]] = lshr exact i16 [[X:%.*]], 15 ; CHECK-NEXT: ret i16 [[LSHR]] ; %zext = zext i16 %x to i32 %lshr = lshr exact i32 %zext, 15 %trunc = trunc i32 %lshr to i16 ret i16 %trunc } ; Negative test define i16 @lshr_negative_operand(i16 %x) { ; CHECK-LABEL: @lshr_negative_operand( ; CHECK-NEXT: [[ZEXT:%.*]] = zext i16 [[X:%.*]] to i32 ; CHECK-NEXT: [[XOR:%.*]] = xor i32 -1, [[ZEXT]] ; CHECK-NEXT: [[LSHR2:%.*]] = lshr i32 [[XOR]], 2 ; CHECK-NEXT: [[TRUNC:%.*]] = trunc i32 [[LSHR2]] to i16 ; CHECK-NEXT: ret i16 [[TRUNC]] ; %zext = zext i16 %x to i32 %xor = xor i32 -1, %zext %lshr2 = lshr i32 %xor, 2 %trunc = trunc i32 %lshr2 to i16 ret i16 %trunc } ; We may encounter unoptimized IR as below, ; so don't crash by assuming that we can ; apply instruction flags (exact) if there ; is no instruction. define i8 @non_canonical_crash() { ; CHECK-LABEL: @non_canonical_crash( ; CHECK-NEXT: ret i8 8 ; %sh = lshr i32 33, 2 %tr = trunc i32 %sh to i8 ret i8 %tr }