[llvm-commits] [llvm] r99756 - in /llvm/trunk: test/CodeGen/X86/2007-04-25-MMX-PADDQ.ll utils/TableGen/CodeGenDAGPatterns.cpp

[Chris Lattner]

Author: lattner
Date: Sun Mar 28 03:38:32 2010
New Revision: 99756

URL: http://llvm.org/viewvc/llvm-project?rev=99756&view=rev
Log:
teach tblgen to allow patterns like (add (i32 (bitconvert (i32 GPR))), 4), 
transforming it into (add (i32 GPR), 4).  This allows us to write type
generic multi patterns and have tblgen automatically drop the bitconvert
in the case when the types align.  This allows us to fold an extra load
in the changed testcase.

Modified:
    llvm/trunk/test/CodeGen/X86/2007-04-25-MMX-PADDQ.ll
    llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp

Modified: llvm/trunk/test/CodeGen/X86/2007-04-25-MMX-PADDQ.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2007-04-25-MMX-PADDQ.ll?rev=99756&r1=99755&r2=99756&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/2007-04-25-MMX-PADDQ.ll (original)
+++ llvm/trunk/test/CodeGen/X86/2007-04-25-MMX-PADDQ.ll Sun Mar 28 03:38:32 2010
@@ -1,12 +1,16 @@
-; RUN: llc < %s -o - -march=x86 -mattr=+mmx | grep paddq | count 2
-; RUN: llc < %s -o - -march=x86 -mattr=+mmx | grep movq | count 2
+; RUN: llc < %s -o - -march=x86 -mattr=+mmx | FileCheck %s
 
-define <1 x i64> @unsigned_add3(<1 x i64>* %a, <1 x i64>* %b, i32 %count) {
+define <1 x i64> @unsigned_add3(<1 x i64>* %a, <1 x i64>* %b, i32 %count) nounwind {
 entry:
 	%tmp2942 = icmp eq i32 %count, 0		; <i1> [#uses=1]
 	br i1 %tmp2942, label %bb31, label %bb26
 
 bb26:		; preds = %bb26, %entry
+
+; CHECK:  movq	({{.*}},8), %mm
+; CHECK:  paddq	({{.*}},8), %mm
+; CHECK:  paddq	%mm{{[0-7]}}, %mm
+
 	%i.037.0 = phi i32 [ 0, %entry ], [ %tmp25, %bb26 ]		; <i32> [#uses=3]
 	%sum.035.0 = phi <1 x i64> [ zeroinitializer, %entry ], [ %tmp22, %bb26 ]		; <<1 x i64>> [#uses=1]
 	%tmp13 = getelementptr <1 x i64>* %b, i32 %i.037.0		; <<1 x i64>*> [#uses=1]

Modified: llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp?rev=99756&r1=99755&r2=99756&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp (original)
+++ llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp Sun Mar 28 03:38:32 2010
@@ -1591,6 +1591,40 @@
   return Result;
 }
 
+/// SimplifyTree - See if we can simplify this tree to eliminate something that
+/// will never match in favor of something obvious that will.  This is here
+/// strictly as a convenience to target authors because it allows them to write
+/// more type generic things and have useless type casts fold away.
+///
+/// This returns true if any change is made.
+static bool SimplifyTree(TreePatternNode *&N) {
+  if (N->isLeaf())
+    return false;
+
+  // If we have a bitconvert with a resolved type and if the source and
+  // destination types are the same, then the bitconvert is useless, remove it.
+  if (N->getOperator()->getName() == "bitconvert" &&
+      N->getNumChildren() > 0 && // FIXME
+      N->getExtType(0).isConcrete() &&
+      N->getExtType(0) == N->getChild(0)->getExtType(0) &&
+      N->getName().empty()) {
+    N = N->getChild(0);
+    SimplifyTree(N);
+    return true;
+  }
+
+  // Walk all children.
+  bool MadeChange = false;
+  for (unsigned i = 0, e = N->getNumChildren(); i != e; ++i) {
+    TreePatternNode *Child = N->getChild(i);
+    MadeChange |= SimplifyTree(Child);
+    N->setChild(i, Child);
+  }
+  return MadeChange;
+}
+
+
+
 /// InferAllTypes - Infer/propagate as many types throughout the expression
 /// patterns as possible.  Return true if all types are inferred, false
 /// otherwise.  Throw an exception if a type contradiction is found.
@@ -1602,8 +1636,10 @@
   bool MadeChange = true;
   while (MadeChange) {
     MadeChange = false;
-    for (unsigned i = 0, e = Trees.size(); i != e; ++i)
+    for (unsigned i = 0, e = Trees.size(); i != e; ++i) {
       MadeChange |= Trees[i]->ApplyTypeConstraints(*this, false);
+      MadeChange |= SimplifyTree(Trees[i]);
+    }
 
     // If there are constraints on our named nodes, apply them.
     for (StringMap<SmallVector<TreePatternNode*,1> >::iterator