; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=instsimplify -S -data-layout="E" | FileCheck %s --check-prefixes=CHECK,BIGENDIAN ; RUN: opt < %s -passes=instsimplify -S -data-layout="e" | FileCheck %s --check-prefixes=CHECK,LITTLEENDIAN ; If any bits of the shift amount are known to make it exceed or equal ; the number of bits in the type, the shift causes undefined behavior. define i32 @shl_amount_is_known_bogus(i32 %a, i32 %b) { ; CHECK-LABEL: @shl_amount_is_known_bogus( ; CHECK-NEXT: ret i32 poison ; %or = or i32 %b, 32 %shl = shl i32 %a, %or ret i32 %shl } ; Check some weird types and the other shift ops. define i31 @lshr_amount_is_known_bogus(i31 %a, i31 %b) { ; CHECK-LABEL: @lshr_amount_is_known_bogus( ; CHECK-NEXT: ret i31 poison ; %or = or i31 %b, 31 %shr = lshr i31 %a, %or ret i31 %shr } define i33 @ashr_amount_is_known_bogus(i33 %a, i33 %b) { ; CHECK-LABEL: @ashr_amount_is_known_bogus( ; CHECK-NEXT: ret i33 poison ; %or = or i33 %b, 33 %shr = ashr i33 %a, %or ret i33 %shr } ; If all valid bits of the shift amount are known 0, there's no shift. ; It doesn't matter if high bits are set because that would be undefined. ; Therefore, the only possible valid result of these shifts is %a. define i16 @ashr_amount_is_zero(i16 %a, i16 %b) { ; CHECK-LABEL: @ashr_amount_is_zero( ; CHECK-NEXT: ret i16 [[A:%.*]] ; %and = and i16 %b, 65520 ; 0xfff0 %shr = ashr i16 %a, %and ret i16 %shr } define i300 @lshr_amount_is_zero(i300 %a, i300 %b) { ; CHECK-LABEL: @lshr_amount_is_zero( ; CHECK-NEXT: ret i300 [[A:%.*]] ; %and = and i300 %b, 2048 %shr = lshr i300 %a, %and ret i300 %shr } define i9 @shl_amount_is_zero(i9 %a, i9 %b) { ; CHECK-LABEL: @shl_amount_is_zero( ; CHECK-NEXT: ret i9 [[A:%.*]] ; %and = and i9 %b, 496 ; 0x1f0 %shl = shl i9 %a, %and ret i9 %shl } ; Verify that we've calculated the log2 boundary of valid bits correctly for a weird type. define i9 @shl_amount_is_not_known_zero(i9 %a, i9 %b) { ; CHECK-LABEL: @shl_amount_is_not_known_zero( ; CHECK-NEXT: [[AND:%.*]] = and i9 [[B:%.*]], -8 ; CHECK-NEXT: [[SHL:%.*]] = shl i9 [[A:%.*]], [[AND]] ; CHECK-NEXT: ret i9 [[SHL]] ; %and = and i9 %b, 504 ; 0x1f8 %shl = shl i9 %a, %and ret i9 %shl } ; For vectors, we need all scalar elements to meet the requirements to optimize. define <2 x i32> @ashr_vector_bogus(<2 x i32> %a, <2 x i32> %b) { ; CHECK-LABEL: @ashr_vector_bogus( ; CHECK-NEXT: ret <2 x i32> poison ; %or = or <2 x i32> %b, <i32 32, i32 32> %shr = ashr <2 x i32> %a, %or ret <2 x i32> %shr } ; FIXME: This is undef, but computeKnownBits doesn't handle the union. define <2 x i32> @shl_vector_bogus(<2 x i32> %a, <2 x i32> %b) { ; CHECK-LABEL: @shl_vector_bogus( ; CHECK-NEXT: [[OR:%.*]] = or <2 x i32> [[B:%.*]], <i32 32, i32 64> ; CHECK-NEXT: [[SHL:%.*]] = shl <2 x i32> [[A:%.*]], [[OR]] ; CHECK-NEXT: ret <2 x i32> [[SHL]] ; %or = or <2 x i32> %b, <i32 32, i32 64> %shl = shl <2 x i32> %a, %or ret <2 x i32> %shl } define <2 x i32> @lshr_vector_zero(<2 x i32> %a, <2 x i32> %b) { ; CHECK-LABEL: @lshr_vector_zero( ; CHECK-NEXT: ret <2 x i32> [[A:%.*]] ; %and = and <2 x i32> %b, <i32 64, i32 256> %shr = lshr <2 x i32> %a, %and ret <2 x i32> %shr } ; Make sure that weird vector types work too. define <2 x i15> @shl_vector_zero(<2 x i15> %a, <2 x i15> %b) { ; CHECK-LABEL: @shl_vector_zero( ; CHECK-NEXT: ret <2 x i15> [[A:%.*]] ; %and = and <2 x i15> %b, <i15 1024, i15 1024> %shl = shl <2 x i15> %a, %and ret <2 x i15> %shl } define <2 x i32> @shl_vector_for_real(<2 x i32> %a, <2 x i32> %b) { ; CHECK-LABEL: @shl_vector_for_real( ; CHECK-NEXT: [[AND:%.*]] = and <2 x i32> [[B:%.*]], <i32 3, i32 3> ; CHECK-NEXT: [[SHL:%.*]] = shl <2 x i32> [[A:%.*]], [[AND]] ; CHECK-NEXT: ret <2 x i32> [[SHL]] ; %and = and <2 x i32> %b, <i32 3, i32 3> ; a necessary mask op %shl = shl <2 x i32> %a, %and ret <2 x i32> %shl } ; We calculate the valid bits of the shift using log2, and log2 of 1 (the type width) is 0. ; That should be ok. Either the shift amount is 0 or invalid (1), so we can always return %a. define i1 @shl_i1(i1 %a, i1 %b) { ; CHECK-LABEL: @shl_i1( ; CHECK-NEXT: ret i1 [[A:%.*]] ; %shl = shl i1 %a, %b ret i1 %shl } ; The following cases only get folded by InstCombine, ; see InstCombine/lshr.ll. declare i32 @llvm.cttz.i32(i32, i1) nounwind readnone declare i32 @llvm.ctlz.i32(i32, i1) nounwind readnone declare <2 x i8> @llvm.cttz.v2i8(<2 x i8>, i1) nounwind readnone declare <2 x i8> @llvm.ctlz.v2i8(<2 x i8>, i1) nounwind readnone define i32 @lshr_ctlz_zero_is_undef(i32 %x) { ; CHECK-LABEL: @lshr_ctlz_zero_is_undef( ; CHECK-NEXT: [[CT:%.*]] = call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 true) ; CHECK-NEXT: [[SH:%.*]] = lshr i32 [[CT]], 5 ; CHECK-NEXT: ret i32 [[SH]] ; %ct = call i32 @llvm.ctlz.i32(i32 %x, i1 true) %sh = lshr i32 %ct, 5 ret i32 %sh } define i32 @lshr_cttz_zero_is_undef(i32 %x) { ; CHECK-LABEL: @lshr_cttz_zero_is_undef( ; CHECK-NEXT: [[CT:%.*]] = call i32 @llvm.cttz.i32(i32 [[X:%.*]], i1 true) ; CHECK-NEXT: [[SH:%.*]] = lshr i32 [[CT]], 5 ; CHECK-NEXT: ret i32 [[SH]] ; %ct = call i32 @llvm.cttz.i32(i32 %x, i1 true) %sh = lshr i32 %ct, 5 ret i32 %sh } define <2 x i8> @lshr_ctlz_zero_is_undef_splat_vec(<2 x i8> %x) { ; CHECK-LABEL: @lshr_ctlz_zero_is_undef_splat_vec( ; CHECK-NEXT: [[CT:%.*]] = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> [[X:%.*]], i1 true) ; CHECK-NEXT: [[SH:%.*]] = lshr <2 x i8> [[CT]], <i8 3, i8 3> ; CHECK-NEXT: ret <2 x i8> [[SH]] ; %ct = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> %x, i1 true) %sh = lshr <2 x i8> %ct, <i8 3, i8 3> ret <2 x i8> %sh } define i8 @lshr_ctlz_zero_is_undef_vec(<2 x i8> %x) { ; CHECK-LABEL: @lshr_ctlz_zero_is_undef_vec( ; CHECK-NEXT: [[CT:%.*]] = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> [[X:%.*]], i1 true) ; CHECK-NEXT: [[SH:%.*]] = lshr <2 x i8> [[CT]], <i8 3, i8 0> ; CHECK-NEXT: [[EX:%.*]] = extractelement <2 x i8> [[SH]], i32 0 ; CHECK-NEXT: ret i8 [[EX]] ; %ct = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> %x, i1 true) %sh = lshr <2 x i8> %ct, <i8 3, i8 0> %ex = extractelement <2 x i8> %sh, i32 0 ret i8 %ex } define <2 x i8> @lshr_cttz_zero_is_undef_splat_vec(<2 x i8> %x) { ; CHECK-LABEL: @lshr_cttz_zero_is_undef_splat_vec( ; CHECK-NEXT: [[CT:%.*]] = call <2 x i8> @llvm.cttz.v2i8(<2 x i8> [[X:%.*]], i1 true) ; CHECK-NEXT: [[SH:%.*]] = lshr <2 x i8> [[CT]], <i8 3, i8 3> ; CHECK-NEXT: ret <2 x i8> [[SH]] ; %ct = call <2 x i8> @llvm.cttz.v2i8(<2 x i8> %x, i1 true) %sh = lshr <2 x i8> %ct, <i8 3, i8 3> ret <2 x i8> %sh } define i8 @lshr_cttz_zero_is_undef_vec(<2 x i8> %x) { ; CHECK-LABEL: @lshr_cttz_zero_is_undef_vec( ; CHECK-NEXT: [[CT:%.*]] = call <2 x i8> @llvm.cttz.v2i8(<2 x i8> [[X:%.*]], i1 true) ; CHECK-NEXT: [[SH:%.*]] = lshr <2 x i8> [[CT]], <i8 3, i8 0> ; CHECK-NEXT: [[EX:%.*]] = extractelement <2 x i8> [[SH]], i32 0 ; CHECK-NEXT: ret i8 [[EX]] ; %ct = call <2 x i8> @llvm.cttz.v2i8(<2 x i8> %x, i1 true) %sh = lshr <2 x i8> %ct, <i8 3, i8 0> %ex = extractelement <2 x i8> %sh, i32 0 ret i8 %ex } ; The shift amount is 0 on either of high/low bytes. The middle byte doesn't matter. define i24 @bitcast_noshift_scalar(<3 x i8> %v1, i24 %v2) { ; CHECK-LABEL: @bitcast_noshift_scalar( ; CHECK-NEXT: ret i24 [[V2:%.*]] ; %c = insertelement <3 x i8> poison, i8 0, i64 0 %s = shufflevector <3 x i8> %v1, <3 x i8> %c, <3 x i32> <i32 3, i32 1, i32 3> %b = bitcast <3 x i8> %s to i24 %r = shl i24 %v2, %b ret i24 %r } ; The shift amount is 0 on low byte of big-endian and unknown on little-endian. define i24 @bitcast_noshift_scalar_bigend(<3 x i8> %v1, i24 %v2) { ; BIGENDIAN-LABEL: @bitcast_noshift_scalar_bigend( ; BIGENDIAN-NEXT: ret i24 [[V2:%.*]] ; ; LITTLEENDIAN-LABEL: @bitcast_noshift_scalar_bigend( ; LITTLEENDIAN-NEXT: [[S:%.*]] = shufflevector <3 x i8> [[V1:%.*]], <3 x i8> <i8 0, i8 poison, i8 poison>, <3 x i32> <i32 0, i32 1, i32 3> ; LITTLEENDIAN-NEXT: [[B:%.*]] = bitcast <3 x i8> [[S]] to i24 ; LITTLEENDIAN-NEXT: [[R:%.*]] = shl i24 [[V2:%.*]], [[B]] ; LITTLEENDIAN-NEXT: ret i24 [[R]] ; %c = insertelement <3 x i8> poison, i8 0, i64 0 %s = shufflevector <3 x i8> %v1, <3 x i8> %c, <3 x i32> <i32 0, i32 1, i32 3> %b = bitcast <3 x i8> %s to i24 %r = shl i24 %v2, %b ret i24 %r } ; The shift amount is 0 on low byte of little-endian and unknown on big-endian. define i24 @bitcast_noshift_scalar_littleend(<3 x i8> %v1, i24 %v2) { ; BIGENDIAN-LABEL: @bitcast_noshift_scalar_littleend( ; BIGENDIAN-NEXT: [[S:%.*]] = shufflevector <3 x i8> [[V1:%.*]], <3 x i8> <i8 0, i8 poison, i8 poison>, <3 x i32> <i32 3, i32 1, i32 2> ; BIGENDIAN-NEXT: [[B:%.*]] = bitcast <3 x i8> [[S]] to i24 ; BIGENDIAN-NEXT: [[R:%.*]] = shl i24 [[V2:%.*]], [[B]] ; BIGENDIAN-NEXT: ret i24 [[R]] ; ; LITTLEENDIAN-LABEL: @bitcast_noshift_scalar_littleend( ; LITTLEENDIAN-NEXT: ret i24 [[V2:%.*]] ; %c = insertelement <3 x i8> poison, i8 0, i64 0 %s = shufflevector <3 x i8> %v1, <3 x i8> %c, <3 x i32> <i32 3, i32 1, i32 2> %b = bitcast <3 x i8> %s to i24 %r = shl i24 %v2, %b ret i24 %r } ; The shift amount is known 24 on little-endian and known 24<<16 on big-endian ; across all vector elements, so it's an overshift either way. define <3 x i24> @bitcast_overshift_vector(<9 x i8> %v1, <3 x i24> %v2) { ; CHECK-LABEL: @bitcast_overshift_vector( ; CHECK-NEXT: ret <3 x i24> poison ; %c = insertelement <9 x i8> poison, i8 24, i64 0 %s = shufflevector <9 x i8> %v1, <9 x i8> %c, <9 x i32> <i32 9, i32 1, i32 2, i32 9, i32 4, i32 5, i32 9, i32 7, i32 8> %b = bitcast <9 x i8> %s to <3 x i24> %r = shl <3 x i24> %v2, %b ret <3 x i24> %r } ; The shift amount is known 23 on little-endian and known 23<<16 on big-endian ; across all vector elements, so it's an overshift for big-endian. define <3 x i24> @bitcast_overshift_vector_bigend(<9 x i8> %v1, <3 x i24> %v2) { ; BIGENDIAN-LABEL: @bitcast_overshift_vector_bigend( ; BIGENDIAN-NEXT: ret <3 x i24> poison ; ; LITTLEENDIAN-LABEL: @bitcast_overshift_vector_bigend( ; LITTLEENDIAN-NEXT: [[S:%.*]] = shufflevector <9 x i8> [[V1:%.*]], <9 x i8> <i8 23, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison>, <9 x i32> <i32 9, i32 1, i32 2, i32 9, i32 4, i32 5, i32 9, i32 7, i32 8> ; LITTLEENDIAN-NEXT: [[B:%.*]] = bitcast <9 x i8> [[S]] to <3 x i24> ; LITTLEENDIAN-NEXT: [[R:%.*]] = shl <3 x i24> [[V2:%.*]], [[B]] ; LITTLEENDIAN-NEXT: ret <3 x i24> [[R]] ; %c = insertelement <9 x i8> poison, i8 23, i64 0 %s = shufflevector <9 x i8> %v1, <9 x i8> %c, <9 x i32> <i32 9, i32 1, i32 2, i32 9, i32 4, i32 5, i32 9, i32 7, i32 8> %b = bitcast <9 x i8> %s to <3 x i24> %r = shl <3 x i24> %v2, %b ret <3 x i24> %r } ; The shift amount is known 23 on big-endian and known 23<<16 on little-endian ; across all vector elements, so it's an overshift for little-endian. define <3 x i24> @bitcast_overshift_vector_littleend(<9 x i8> %v1, <3 x i24> %v2) { ; BIGENDIAN-LABEL: @bitcast_overshift_vector_littleend( ; BIGENDIAN-NEXT: [[S:%.*]] = shufflevector <9 x i8> [[V1:%.*]], <9 x i8> <i8 23, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison>, <9 x i32> <i32 0, i32 1, i32 9, i32 3, i32 4, i32 9, i32 6, i32 7, i32 9> ; BIGENDIAN-NEXT: [[B:%.*]] = bitcast <9 x i8> [[S]] to <3 x i24> ; BIGENDIAN-NEXT: [[R:%.*]] = shl <3 x i24> [[V2:%.*]], [[B]] ; BIGENDIAN-NEXT: ret <3 x i24> [[R]] ; ; LITTLEENDIAN-LABEL: @bitcast_overshift_vector_littleend( ; LITTLEENDIAN-NEXT: ret <3 x i24> poison ; %c = insertelement <9 x i8> poison, i8 23, i64 0 %s = shufflevector <9 x i8> %v1, <9 x i8> %c, <9 x i32> <i32 0, i32 1, i32 9, i32 3, i32 4, i32 9, i32 6, i32 7, i32 9> %b = bitcast <9 x i8> %s to <3 x i24> %r = shl <3 x i24> %v2, %b ret <3 x i24> %r } ; Negative test - the shift amount is known 24 or 24<<16 on only 2 out of 3 elements. define <3 x i24> @bitcast_partial_overshift_vector(<9 x i8> %v1, <3 x i24> %v2) { ; CHECK-LABEL: @bitcast_partial_overshift_vector( ; CHECK-NEXT: [[S:%.*]] = shufflevector <9 x i8> [[V1:%.*]], <9 x i8> <i8 24, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison, i8 poison>, <9 x i32> <i32 9, i32 1, i32 2, i32 9, i32 4, i32 5, i32 6, i32 7, i32 8> ; CHECK-NEXT: [[B:%.*]] = bitcast <9 x i8> [[S]] to <3 x i24> ; CHECK-NEXT: [[R:%.*]] = shl <3 x i24> [[V2:%.*]], [[B]] ; CHECK-NEXT: ret <3 x i24> [[R]] ; %c = insertelement <9 x i8> poison, i8 24, i64 0 %s = shufflevector <9 x i8> %v1, <9 x i8> %c, <9 x i32> <i32 9, i32 1, i32 2, i32 9, i32 4, i32 5, i32 6, i32 7, i32 8> %b = bitcast <9 x i8> %s to <3 x i24> %r = shl <3 x i24> %v2, %b ret <3 x i24> %r } ; Negative test - don't know how to look through a cast with non-integer type (but we could handle this...). define <1 x i64> @bitcast_noshift_vector_wrong_type(<2 x float> %v1, <1 x i64> %v2) { ; CHECK-LABEL: @bitcast_noshift_vector_wrong_type( ; CHECK-NEXT: [[S:%.*]] = shufflevector <2 x float> [[V1:%.*]], <2 x float> <float 0.000000e+00, float poison>, <2 x i32> <i32 2, i32 1> ; CHECK-NEXT: [[B:%.*]] = bitcast <2 x float> [[S]] to <1 x i64> ; CHECK-NEXT: [[R:%.*]] = shl <1 x i64> [[V2:%.*]], [[B]] ; CHECK-NEXT: ret <1 x i64> [[R]] ; %c = insertelement <2 x float> poison, float 0.0, i64 0 %s = shufflevector <2 x float> %v1, <2 x float> %c, <2 x i32> <i32 2, i32 1> %b = bitcast <2 x float> %s to <1 x i64> %r = shl <1 x i64> %v2, %b ret <1 x i64> %r }