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[TableGen][GlobalISel] Add rule-wide type inference
The inference is trivial and leverages the MCOI OperandTypes encoded in CodeGenInstructions to infer types across patterns in a CombineRule. It's thus very limited and only supports CodeGenInstructions (but that's the main use case so it's fine). We only try to infer untyped operands in apply patterns when they're temp reg defs, or immediates. Inference always outputs a `TypeOf<$x>` where $x is a named operand from a match pattern.
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‎llvm/include/llvm/Target/GenericOpcodes.td

Lines changed: 7 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -17,6 +17,10 @@
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class GenericInstruction : StandardPseudoInstruction {
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let isPreISelOpcode = true;
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// When all variadic ops share a type with another operand,
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// this is the type they share. Used by MIR patterns type inference.
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TypedOperand variadicOpsType = ?;
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}
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// Provide a variant of an instruction with the same operands, but
@@ -1228,6 +1232,7 @@ def G_UNMERGE_VALUES : GenericInstruction {
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let OutOperandList = (outs type0:$dst0, variable_ops);
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let InOperandList = (ins type1:$src);
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let hasSideEffects = false;
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let variadicOpsType = type0;
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}
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// Insert a smaller register into a larger one at the specified bit-index.
@@ -1245,6 +1250,7 @@ def G_MERGE_VALUES : GenericInstruction {
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let OutOperandList = (outs type0:$dst);
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let InOperandList = (ins type1:$src0, variable_ops);
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let hasSideEffects = false;
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let variadicOpsType = type1;
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}
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/// Create a vector from multiple scalar registers. No implicit
@@ -1254,6 +1260,7 @@ def G_BUILD_VECTOR : GenericInstruction {
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let OutOperandList = (outs type0:$dst);
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let InOperandList = (ins type1:$src0, variable_ops);
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let hasSideEffects = false;
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let variadicOpsType = type1;
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}
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/// Like G_BUILD_VECTOR, but truncates the larger operand types to fit the

‎llvm/include/llvm/Target/GlobalISel/Combine.td

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -796,7 +796,7 @@ def trunc_shift: GICombineRule <
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def mul_by_neg_one: GICombineRule <
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(defs root:$dst),
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(match (G_MUL $dst, $x, -1)),
799-
(apply (G_SUB $dst, (GITypeOf<"$x"> 0), $x))
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(apply (G_SUB $dst, 0, $x))
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>;
801801

802802
// Fold (xor (and x, y), y) -> (and (not x), y)

‎llvm/test/TableGen/GlobalISelCombinerEmitter/pattern-errors.td

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -151,7 +151,7 @@ def bad_imm_too_many_args : GICombineRule<
151151
(match (COPY $x, (i32 0, 0)):$d),
152152
(apply (COPY $x, $b):$d)>;
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154-
// CHECK: :[[@LINE+2]]:{{[0-9]+}}: error: cannot parse immediate '(COPY 0)', 'COPY' is not a ValueType
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// CHECK: :[[@LINE+2]]:{{[0-9]+}}: error: unknown type 'COPY'
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// CHECK: :[[@LINE+1]]:{{[0-9]+}}: error: Failed to parse pattern: '(COPY ?:$x, (COPY 0))
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def bad_imm_not_a_valuetype : GICombineRule<
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(defs root:$a),
@@ -186,7 +186,7 @@ def expected_op_name : GICombineRule<
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(match (G_FNEG $x, i32)),
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(apply (COPY $x, (i32 0)))>;
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189-
// CHECK: :[[@LINE+3]]:{{[0-9]+}}: error: invalid operand type: 'not_a_type' is not a ValueType
189+
// CHECK: :[[@LINE+3]]:{{[0-9]+}}: error: unknown type 'not_a_type'
190190
// CHECK: :[[@LINE+2]]:{{[0-9]+}}: error: Failed to parse pattern: '(G_FNEG ?:$x, not_a_type:$y)'
191191
def not_a_type;
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def bad_mo_type_not_a_valuetype : GICombineRule<

‎llvm/test/TableGen/GlobalISelCombinerEmitter/type-inference.td

Lines changed: 75 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,75 @@
1+
// RUN: llvm-tblgen -I %p/../../../include -gen-global-isel-combiner \
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// RUN: -gicombiner-debug-typeinfer -combiners=MyCombiner %s 2>&1 | \
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// RUN: FileCheck %s
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// Checks reasoning of the inference rules.
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include "llvm/Target/Target.td"
8+
include "llvm/Target/GlobalISel/Combine.td"
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def MyTargetISA : InstrInfo;
11+
def MyTarget : Target { let InstructionSet = MyTargetISA; }
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// CHECK: Rule Operand Type Equivalence Classes for inference_mul_by_neg_one:
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// CHECK-NEXT: __inference_mul_by_neg_one_match_0: [dst, x]
15+
// CHECK-NEXT: __inference_mul_by_neg_one_apply_0: [dst, x]
16+
// CHECK-NEXT: (merging [dst, x] | [dst, x])
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// CHECK-NEXT: Result: [dst, x]
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// CHECK-NEXT: INFER: imm 0 -> GITypeOf<$x>
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// CHECK-NEXT: Apply patterns for rule inference_mul_by_neg_one after inference:
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// CHECK-NEXT: (CodeGenInstructionPattern name:__inference_mul_by_neg_one_apply_0 G_SUB operands:[<def>$dst, (GITypeOf<$x> 0), $x])
21+
def inference_mul_by_neg_one: GICombineRule <
22+
(defs root:$dst),
23+
(match (G_MUL $dst, $x, -1)),
24+
(apply (G_SUB $dst, 0, $x))
25+
>;
26+
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// CHECK: Rule Operand Type Equivalence Classes for infer_complex_tempreg:
28+
// CHECK-NEXT: __infer_complex_tempreg_match_0: [dst] [x, y, z]
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// CHECK-NEXT: __infer_complex_tempreg_apply_0: [tmp2] [x, y]
30+
// CHECK-NEXT: __infer_complex_tempreg_apply_1: [tmp, tmp2]
31+
// CHECK-NEXT: __infer_complex_tempreg_apply_2: [dst, tmp]
32+
// CHECK-NEXT: (merging [dst] | [dst, tmp])
33+
// CHECK-NEXT: (merging [x, y, z] | [x, y])
34+
// CHECK-NEXT: (merging [tmp2] | [tmp, tmp2])
35+
// CHECK-NEXT: (merging [dst, tmp] | [tmp2, tmp])
36+
// CHECK-NEXT: Result: [dst, tmp, tmp2] [x, y, z]
37+
// CHECK-NEXT: INFER: MachineOperand $tmp2 -> GITypeOf<$dst>
38+
// CHECK-NEXT: INFER: MachineOperand $tmp -> GITypeOf<$dst>
39+
// CHECK-NEXT: Apply patterns for rule infer_complex_tempreg after inference:
40+
// CHECK-NEXT: (CodeGenInstructionPattern name:__infer_complex_tempreg_apply_0 G_BUILD_VECTOR operands:[<def>GITypeOf<$dst>:$tmp2, $x, $y])
41+
// CHECK-NEXT: (CodeGenInstructionPattern name:__infer_complex_tempreg_apply_1 G_FNEG operands:[<def>GITypeOf<$dst>:$tmp, GITypeOf<$dst>:$tmp2])
42+
// CHECK-NEXT: (CodeGenInstructionPattern name:__infer_complex_tempreg_apply_2 G_FNEG operands:[<def>$dst, GITypeOf<$dst>:$tmp])
43+
def infer_complex_tempreg: GICombineRule <
44+
(defs root:$dst),
45+
(match (G_MERGE_VALUES $dst, $x, $y, $z)),
46+
(apply (G_BUILD_VECTOR $tmp2, $x, $y),
47+
(G_FNEG $tmp, $tmp2),
48+
(G_FNEG $dst, $tmp))
49+
>;
50+
51+
// CHECK: Rule Operand Type Equivalence Classes for infer_variadic_outs:
52+
// CHECK-NEXT: __infer_variadic_outs_match_0: [x, y] [vec]
53+
// CHECK-NEXT: __infer_variadic_outs_match_1: [dst, x]
54+
// CHECK-NEXT: __infer_variadic_outs_apply_0: [tmp, y]
55+
// CHECK-NEXT: __infer_variadic_outs_apply_1: (empty)
56+
// CHECK-NEXT: (merging [x, y] | [dst, x])
57+
// CHECK-NEXT: (merging [x, y, dst] | [tmp, y])
58+
// CHECK-NEXT: Result: [x, y, dst, tmp] [vec]
59+
// CHECK-NEXT: INFER: MachineOperand $tmp -> GITypeOf<$x>
60+
// CHECK-NEXT: Apply patterns for rule infer_variadic_outs after inference:
61+
// CHECK-NEXT: (CodeGenInstructionPattern name:__infer_variadic_outs_apply_0 G_FNEG operands:[<def>GITypeOf<$x>:$tmp, $y])
62+
// CHECK-NEXT: (CodeGenInstructionPattern name:__infer_variadic_outs_apply_1 COPY operands:[<def>$dst, GITypeOf<$x>:$tmp])
63+
def infer_variadic_outs: GICombineRule <
64+
(defs root:$dst),
65+
(match (G_UNMERGE_VALUES $x, $y, $vec),
66+
(G_FNEG $dst, $x)),
67+
(apply (G_FNEG $tmp, $y),
68+
(COPY $dst, $tmp))
69+
>;
70+
71+
def MyCombiner: GICombiner<"GenMyCombiner", [
72+
inference_mul_by_neg_one,
73+
infer_complex_tempreg,
74+
infer_variadic_outs
75+
]>;

‎llvm/test/TableGen/GlobalISelCombinerEmitter/typeof-errors.td

Lines changed: 5 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,8 @@ include "llvm/Target/GlobalISel/Combine.td"
88
def MyTargetISA : InstrInfo;
99
def MyTarget : Target { let InstructionSet = MyTargetISA; }
1010

11-
// CHECK: :[[@LINE+1]]:{{[0-9]+}}: error: invalid operand name format 'unknown' in GITypeOf: expected '$' followed by an operand name
11+
// CHECK: :[[@LINE+2]]:{{[0-9]+}}: error: invalid operand name format 'unknown' in GITypeOf: expected '$' followed by an operand name
12+
// CHECK: :[[@LINE+1]]:{{[0-9]+}}: error: Failed to parse pattern: '(G_ANYEXT ?:$dst, (anonymous_
1213
def NoDollarSign : GICombineRule<
1314
(defs root:$dst),
1415
(match (G_ZEXT $dst, $src)),
@@ -47,7 +48,9 @@ def InferredUseInMatch : GICombineRule<
4748
(match (G_ZEXT $dst, $src)),
4849
(apply (G_ANYEXT $dst, GITypeOf<"$dst">:$src))>;
4950

50-
// CHECK: :[[@LINE+1]]:{{[0-9]+}}: error: conflicting types for operand 'src': first seen with 'i32' in '__InferenceConflict_match_0, now seen with 'GITypeOf<$dst>' in '__InferenceConflict_apply_0'
51+
// CHECK: :[[@LINE+3]]:{{[0-9]+}}: error: conflicting types for operand 'src': 'i32' vs 'GITypeOf<$dst>'
52+
// CHECK: :[[@LINE+2]]:{{[0-9]+}}: note: 'src' seen with type 'GITypeOf<$dst>' in '__InferenceConflict_apply_0'
53+
// CHECK: :[[@LINE+1]]:{{[0-9]+}}: note: 'src' seen with type 'i32' in '__InferenceConflict_match_0'
5154
def InferenceConflict : GICombineRule<
5255
(defs root:$dst),
5356
(match (G_ZEXT $dst, i32:$src)),

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