[llvm-commits] [llvm] r98168 - in /llvm/trunk: lib/Target/XCore/XCoreISelLowering.cpp test/CodeGen/XCore/addsub64.ll

[Richard Osborne]

Author: friedgold
Date: Wed Mar 10 12:12:27 2010
New Revision: 98168

URL: http://llvm.org/viewvc/llvm-project?rev=98168&view=rev
Log:
Handle MVT::i64 type in DAG combine for ISD::ADD. Fold 64 bit
expression add(add(mul(x,y),a),b) -> lmul(x,y,a,b) if all
operands are zero extended.

Modified:
    llvm/trunk/lib/Target/XCore/XCoreISelLowering.cpp
    llvm/trunk/test/CodeGen/XCore/addsub64.ll

Modified: llvm/trunk/lib/Target/XCore/XCoreISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/XCore/XCoreISelLowering.cpp?rev=98168&r1=98167&r2=98168&view=diff
==============================================================================
--- llvm/trunk/lib/Target/XCore/XCoreISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/XCore/XCoreISelLowering.cpp Wed Mar 10 12:12:27 2010
@@ -1342,11 +1342,13 @@
   }
   break;
   case ISD::ADD: {
-    // Fold expressions such as add(add(mul(x,y),a),b) -> lmul(x, y, a, b).
+    // Fold 32 bit expressions such as add(add(mul(x,y),a),b) ->
+    // lmul(x, y, a, b). The high result of lmul will be ignored.
     // This is only profitable if the intermediate results are unused
     // elsewhere.
     SDValue Mul0, Mul1, Addend0, Addend1;
-    if (isADDADDMUL(SDValue(N, 0), Mul0, Mul1, Addend0, Addend1, true)) {
+    if (N->getValueType(0) == MVT::i32 &&
+        isADDADDMUL(SDValue(N, 0), Mul0, Mul1, Addend0, Addend1, true)) {
       SDValue Zero = DAG.getConstant(0, MVT::i32);
       SDValue Ignored = DAG.getNode(XCoreISD::LMUL, dl,
                                     DAG.getVTList(MVT::i32, MVT::i32), Mul0,
@@ -1354,6 +1356,31 @@
       SDValue Result(Ignored.getNode(), 1);
       return Result;
     }
+    APInt HighMask = APInt::getHighBitsSet(64, 32);
+    // Fold 64 bit expression such as add(add(mul(x,y),a),b) ->
+    // lmul(x, y, a, b) if all operands are zero-extended. We do this
+    // before type legalization as it is messy to match the operands after
+    // that.
+    if (N->getValueType(0) == MVT::i64 &&
+        isADDADDMUL(SDValue(N, 0), Mul0, Mul1, Addend0, Addend1, false) &&
+        DAG.MaskedValueIsZero(Mul0, HighMask) &&
+        DAG.MaskedValueIsZero(Mul1, HighMask) &&
+        DAG.MaskedValueIsZero(Addend0, HighMask) &&
+        DAG.MaskedValueIsZero(Addend1, HighMask)) {
+      SDValue Mul0L = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
+                                  Mul0, DAG.getConstant(0, MVT::i32));
+      SDValue Mul1L = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
+                                  Mul1, DAG.getConstant(0, MVT::i32));
+      SDValue Addend0L = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
+                                     Addend0, DAG.getConstant(0, MVT::i32));
+      SDValue Addend1L = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32,
+                                     Addend1, DAG.getConstant(0, MVT::i32));
+      SDValue Hi = DAG.getNode(XCoreISD::LMUL, dl,
+                               DAG.getVTList(MVT::i32, MVT::i32), Mul0L, Mul1L,
+                               Addend0L, Addend1L);
+      SDValue Lo(Hi.getNode(), 1);
+      return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lo, Hi);
+    }
   }
   break;
   case ISD::STORE: {

Modified: llvm/trunk/test/CodeGen/XCore/addsub64.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/XCore/addsub64.ll?rev=98168&r1=98167&r2=98168&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/XCore/addsub64.ll (original)
+++ llvm/trunk/test/CodeGen/XCore/addsub64.ll Wed Mar 10 12:12:27 2010
@@ -42,3 +42,18 @@
 ; CHECK: maccs:
 ; CHECK: maccs r1, r0, r3, r2
 ; CHECK-NEXT: retsp 0
+
+define i64 @lmul(i32 %a, i32 %b, i32 %c, i32 %d) {
+entry:
+	%0 = zext i32 %a to i64
+	%1 = zext i32 %b to i64
+	%2 = zext i32 %c to i64
+	%3 = zext i32 %d to i64
+	%4 = mul i64 %1, %0
+	%5 = add i64 %4, %2
+	%6 = add i64 %5, %3
+	ret i64 %6
+}
+; CHECK: lmul:
+; CHECK: lmul r1, r0, r1, r0, r2, r3
+; CHECK-NEXT: retsp 0