Extend TableGen instruction selection matcher to improve handling
of complex instruction operands (e.g. address modes).
Currently, if a Pat pattern creates an instruction that has a complex
operand (i.e. one that consists of multiple sub-operands at the MI
level), this operand must match a ComplexPattern DAG pattern with the
correct number of output operands.
This commit extends TableGen to alternatively allow match a complex
operands against multiple separate operands at the DAG level.
This allows using Pat patterns to match pre-increment nodes like
pre_store (which must have separate operands at the DAG level) onto
an instruction pattern that uses a multi-operand memory operand,
like the following example on PowerPC (will be committed as a
follow-on patch):
def STWU : DForm_1<37, (outs ptr_rc:$ea_res), (ins GPRC:$rS, memri:$dst),
"stwu $rS, $dst", LdStStoreUpd, []>,
RegConstraint<"$dst.reg = $ea_res">, NoEncode<"$ea_res">;
def : Pat<(pre_store GPRC:$rS, ptr_rc:$ptrreg, iaddroff:$ptroff),
(STWU GPRC:$rS, iaddroff:$ptroff, ptr_rc:$ptrreg)>;
Here, the pair of "ptroff" and "ptrreg" operands is matched onto the
complex operand "dst" of class "memri" in the "STWU" instruction.
Approved by Jakob Stoklund Olesen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177428 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/DAGISelMatcherGen.cpp b/utils/TableGen/DAGISelMatcherGen.cpp
index 38ffa30..8541390 100644
--- a/utils/TableGen/DAGISelMatcherGen.cpp
+++ b/utils/TableGen/DAGISelMatcherGen.cpp
@@ -734,20 +734,33 @@
continue;
}
- const TreePatternNode *Child = N->getChild(ChildNo);
-
// Otherwise this is a normal operand or a predicate operand without
// 'execute always'; emit it.
- unsigned BeforeAddingNumOps = InstOps.size();
- EmitResultOperand(Child, InstOps);
- assert(InstOps.size() > BeforeAddingNumOps && "Didn't add any operands");
- // If the operand is an instruction and it produced multiple results, just
- // take the first one.
- if (!Child->isLeaf() && Child->getOperator()->isSubClassOf("Instruction"))
- InstOps.resize(BeforeAddingNumOps+1);
+ // For operands with multiple sub-operands we may need to emit
+ // multiple child patterns to cover them all. However, ComplexPattern
+ // children may themselves emit multiple MI operands.
+ unsigned NumSubOps = 1;
+ if (OperandNode->isSubClassOf("Operand")) {
+ DagInit *MIOpInfo = OperandNode->getValueAsDag("MIOperandInfo");
+ if (unsigned NumArgs = MIOpInfo->getNumArgs())
+ NumSubOps = NumArgs;
+ }
- ++ChildNo;
+ unsigned FinalNumOps = InstOps.size() + NumSubOps;
+ while (InstOps.size() < FinalNumOps) {
+ const TreePatternNode *Child = N->getChild(ChildNo);
+ unsigned BeforeAddingNumOps = InstOps.size();
+ EmitResultOperand(Child, InstOps);
+ assert(InstOps.size() > BeforeAddingNumOps && "Didn't add any operands");
+
+ // If the operand is an instruction and it produced multiple results, just
+ // take the first one.
+ if (!Child->isLeaf() && Child->getOperator()->isSubClassOf("Instruction"))
+ InstOps.resize(BeforeAddingNumOps+1);
+
+ ++ChildNo;
+ }
}
// If this node has input glue or explicitly specified input physregs, we