For the h-register addressing-mode trick, use the correct value for

any non-address uses of the address value. This fixes 186.crafty.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69094 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 41a3c416f85eeff91313bb6bd08292616f7b4eb4..18a574fc5ae44d64618a57f7c2e4f68c6ffbaa65 100644 (file)
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -1049,6 +1049,9 @@ bool X86DAGToDAGISel::MatchAddress(SDValue N, X86ISelAddressMode &AM,
                                       X, Eight);
         SDValue And = CurDAG->getNode(ISD::AND, dl, N.getValueType(),
                                       Srl, Mask);
+        SDValue ShlCount = CurDAG->getConstant(ScaleLog, MVT::i8);
+        SDValue Shl = CurDAG->getNode(ISD::SHL, dl, N.getValueType(),
+                                      And, ShlCount);
 
         // Insert the new nodes into the topological ordering.
         if (Eight.getNode()->getNodeId() == -1 ||
@@ -1071,7 +1074,17 @@ bool X86DAGToDAGISel::MatchAddress(SDValue N, X86ISelAddressMode &AM,
           CurDAG->RepositionNode(N.getNode(), And.getNode());
           And.getNode()->setNodeId(N.getNode()->getNodeId());
         }
-        CurDAG->ReplaceAllUsesWith(N, And);
+        if (ShlCount.getNode()->getNodeId() == -1 ||
+            ShlCount.getNode()->getNodeId() > X.getNode()->getNodeId()) {
+          CurDAG->RepositionNode(X.getNode(), ShlCount.getNode());
+          ShlCount.getNode()->setNodeId(N.getNode()->getNodeId());
+        }
+        if (Shl.getNode()->getNodeId() == -1 ||
+            Shl.getNode()->getNodeId() > N.getNode()->getNodeId()) {
+          CurDAG->RepositionNode(N.getNode(), Shl.getNode());
+          Shl.getNode()->setNodeId(N.getNode()->getNodeId());
+        }
+        CurDAG->ReplaceAllUsesWith(N, Shl);
         AM.IndexReg = And;
         AM.Scale = (1 << ScaleLog);
         return false;

diff --git a/test/CodeGen/X86/h-registers-2.ll b/test/CodeGen/X86/h-registers-2.ll
new file mode 100644 (file)
index 0000000..12236a2
--- /dev/null
+++ b/test/CodeGen/X86/h-registers-2.ll
@@ -0,0 +1,15 @@
+; RUN: llvm-as < %s | llc -march=x86 > %t
+; grep {movzbl %\[abcd\]h,} %t | count 1
+; grep {shll   \$3,} | count 1
+
+; Use an h register, but don't omit the explicit shift for
+; non-address use(s).
+
+define i32 @foo(i8* %x, i32 %y) nounwind {
+       %t0 = lshr i32 %y, 8            ; <i32> [#uses=1]
+       %t1 = and i32 %t0, 255          ; <i32> [#uses=2]
+        %t2 = shl i32 %t1, 3
+       %t3 = getelementptr i8* %x, i32 %t2             ; <i8*> [#uses=1]
+       store i8 77, i8* %t3, align 4
+       ret i32 %t2
+}