From 721c201bd55ffb73cb2ba8d39e0570fa38c44e15 Mon Sep 17 00:00:00 2001
From: dim <dim@FreeBSD.org>
Date: Wed, 15 Aug 2012 19:34:23 +0000
Subject: Vendor import of llvm trunk r161861:
http://llvm.org/svn/llvm-project/llvm/trunk@161861
---
utils/TableGen/CodeGenDAGPatterns.cpp | 43 +++++++++++++++++++++++++++++++++--
1 file changed, 41 insertions(+), 2 deletions(-)
(limited to 'utils/TableGen/CodeGenDAGPatterns.cpp')
diff --git a/utils/TableGen/CodeGenDAGPatterns.cpp b/utils/TableGen/CodeGenDAGPatterns.cpp
index d4b02fb..34f8a34 100644
--- a/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -2520,6 +2520,37 @@ static void InferFromPattern(const CodeGenInstruction &Inst,
IsVariadic = true; // Can warn if we want.
}
+/// hasNullFragReference - Return true if the DAG has any reference to the
+/// null_frag operator.
+static bool hasNullFragReference(DagInit *DI) {
+ DefInit *OpDef = dynamic_cast<DefInit*>(DI->getOperator());
+ if (!OpDef) return false;
+ Record *Operator = OpDef->getDef();
+
+ // If this is the null fragment, return true.
+ if (Operator->getName() == "null_frag") return true;
+ // If any of the arguments reference the null fragment, return true.
+ for (unsigned i = 0, e = DI->getNumArgs(); i != e; ++i) {
+ DagInit *Arg = dynamic_cast<DagInit*>(DI->getArg(i));
+ if (Arg && hasNullFragReference(Arg))
+ return true;
+ }
+
+ return false;
+}
+
+/// hasNullFragReference - Return true if any DAG in the list references
+/// the null_frag operator.
+static bool hasNullFragReference(ListInit *LI) {
+ for (unsigned i = 0, e = LI->getSize(); i != e; ++i) {
+ DagInit *DI = dynamic_cast<DagInit*>(LI->getElement(i));
+ assert(DI && "non-dag in an instruction Pattern list?!");
+ if (hasNullFragReference(DI))
+ return true;
+ }
+ return false;
+}
+
/// ParseInstructions - Parse all of the instructions, inlining and resolving
/// any fragments involved. This populates the Instructions list with fully
/// resolved instructions.
@@ -2534,8 +2565,11 @@ void CodeGenDAGPatterns::ParseInstructions() {
// If there is no pattern, only collect minimal information about the
// instruction for its operand list. We have to assume that there is one
- // result, as we have no detailed info.
- if (!LI || LI->getSize() == 0) {
+ // result, as we have no detailed info. A pattern which references the
+ // null_frag operator is as-if no pattern were specified. Normally this
+ // is from a multiclass expansion w/ a SDPatternOperator passed in as
+ // null_frag.
+ if (!LI || LI->getSize() == 0 || hasNullFragReference(LI)) {
std::vector<Record*> Results;
std::vector<Record*> Operands;
@@ -2874,6 +2908,11 @@ void CodeGenDAGPatterns::ParsePatterns() {
for (unsigned i = 0, e = Patterns.size(); i != e; ++i) {
Record *CurPattern = Patterns[i];
DagInit *Tree = CurPattern->getValueAsDag("PatternToMatch");
+
+ // If the pattern references the null_frag, there's nothing to do.
+ if (hasNullFragReference(Tree))
+ continue;
+
TreePattern *Pattern = new TreePattern(CurPattern, Tree, true, *this);
// Inline pattern fragments into it.
--
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