[llvm-commits] [llvm] r73024 - in /llvm/trunk: lib/CodeGen/SelectionDAG/LegalizeTypesGeneric.cpp test/CodeGen/X86/2009-06-07-ExpandMMXBitcast.ll

[Eli Friedman]

Author: efriedma
Date: Sun Jun  7 04:41:57 2009
New Revision: 73024

URL: http://llvm.org/viewvc/llvm-project?rev=73024&view=rev
Log:
Tweak the expansion code for BIT_CONVERT to generate better code 
converting from an MMX vector to an i64.


Added:
    llvm/trunk/test/CodeGen/X86/2009-06-07-ExpandMMXBitcast.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeTypesGeneric.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeTypesGeneric.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeTypesGeneric.cpp?rev=73024&r1=73023&r2=73024&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeTypesGeneric.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeTypesGeneric.cpp Sun Jun  7 04:41:57 2009
@@ -92,6 +92,26 @@
     }
   }
 
+  if (InVT.isVector() && OutVT.isInteger()) {
+    // Handle cases like i64 = BIT_CONVERT v1i64 on x86, where the operand
+    // is legal but the result is not.
+    MVT NVT = MVT::getVectorVT(TLI.getTypeToTransformTo(OutVT), 2);
+
+    if (isTypeLegal(NVT)) {
+      SDValue CastInOp = DAG.getNode(ISD::BIT_CONVERT, dl, NVT, InOp);
+      MVT EltNVT = NVT.getVectorElementType();
+      Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltNVT, CastInOp,
+                       DAG.getIntPtrConstant(0));
+      Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltNVT, CastInOp,
+                       DAG.getIntPtrConstant(1));
+
+      if (TLI.isBigEndian())
+        std::swap(Lo, Hi);
+      
+      return;
+    }
+  }
+
   // Lower the bit-convert to a store/load from the stack.
   assert(NOutVT.isByteSized() && "Expanded type not byte sized!");
 

Added: llvm/trunk/test/CodeGen/X86/2009-06-07-ExpandMMXBitcast.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2009-06-07-ExpandMMXBitcast.ll?rev=73024&view=auto

==============================================================================
--- llvm/trunk/test/CodeGen/X86/2009-06-07-ExpandMMXBitcast.ll (added)
+++ llvm/trunk/test/CodeGen/X86/2009-06-07-ExpandMMXBitcast.ll Sun Jun  7 04:41:57 2009
@@ -0,0 +1,10 @@
+; RUN: llvm-as < %s | llc | grep movl | count 2
+
+define i64 @a(i32 %a, i32 %b) nounwind readnone {
+entry:
+	%0 = insertelement <2 x i32> undef, i32 %a, i32 0		; <<2 x i32>> [#uses=1]
+	%1 = insertelement <2 x i32> %0, i32 %b, i32 1		; <<2 x i32>> [#uses=1]
+	%conv = bitcast <2 x i32> %1 to i64		; <i64> [#uses=1]
+	ret i64 %conv
+}
+