From f686d9b71f0aa99578dac9a4dd50b57ece6945fa Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Fri, 27 Oct 2006 21:08:32 +0000
Subject: [PATCH] Fixed a significant bug where unpcklpd is incorrectly used to
 extract element 1 from a v2f64 value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31228 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86ISelLowering.cpp | 11 +++++++++++
 lib/Target/X86/X86ISelLowering.h   |  4 ++++
 lib/Target/X86/X86InstrSSE.td      | 16 ++++++++++------
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index fb2b92ab725..d442a18850b 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2868,6 +2868,17 @@ bool X86::isSplatMask(SDNode *N) {
   return ::isSplatMask(N);
 }
 
+/// isSplatLoMask - Return true if the specified VECTOR_SHUFFLE operand
+/// specifies a splat of zero element.
+bool X86::isSplatLoMask(SDNode *N) {
+  assert(N->getOpcode() == ISD::BUILD_VECTOR);
+
+  for (unsigned i = 0, e = N->getNumOperands(); i < e; ++i) 
+    if (!isUndefOrEqual(N->getOperand(i), 0))
+      return false;
+  return true;
+}
+
 /// getShuffleSHUFImmediate - Return the appropriate immediate to shuffle
 /// the specified isShuffleMask VECTOR_SHUFFLE mask with PSHUF* and SHUFP*
 /// instructions.
diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index 8fd2b52e1cc..6de2964ec78 100644
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -225,6 +225,10 @@ namespace llvm {
    /// specifies a splat of a single element.
    bool isSplatMask(SDNode *N);
 
+   /// isSplatLoMask - Return true if the specified VECTOR_SHUFFLE operand
+   /// specifies a splat of zero element.
+   bool isSplatLoMask(SDNode *N);
+
    /// getShuffleSHUFImmediate - Return the appropriate immediate to shuffle
    /// the specified isShuffleMask VECTOR_SHUFFLE mask with PSHUF* and SHUFP*
    /// instructions.
diff --git a/lib/Target/X86/X86InstrSSE.td b/lib/Target/X86/X86InstrSSE.td
index c2fe9acb5b8..7361c70cdfe 100644
--- a/lib/Target/X86/X86InstrSSE.td
+++ b/lib/Target/X86/X86InstrSSE.td
@@ -104,8 +104,8 @@ def SSE_splat_mask : PatLeaf<(build_vector), [{
   return X86::isSplatMask(N);
 }], SHUFFLE_get_shuf_imm>;
 
-def SSE_splat_v2_mask : PatLeaf<(build_vector), [{
-  return X86::isSplatMask(N);
+def SSE_splat_lo_mask : PatLeaf<(build_vector), [{
+  return X86::isSplatLoMask(N);
 }]>;
 
 def MOVHLPS_shuffle_mask : PatLeaf<(build_vector), [{
@@ -812,13 +812,13 @@ def MOVDDUPrr : S3DI<0x12, MRMSrcReg, (ops VR128:$dst, VR128:$src),
                       "movddup {$src, $dst|$dst, $src}",
                   [(set VR128:$dst, (v2f64 (vector_shuffle
                                             VR128:$src, (undef),
-                                            SSE_splat_v2_mask)))]>;
+                                            SSE_splat_lo_mask)))]>;
 def MOVDDUPrm : S3DI<0x12, MRMSrcMem, (ops VR128:$dst, f64mem:$src),
                   "movddup {$src, $dst|$dst, $src}",
                   [(set VR128:$dst, (v2f64 (vector_shuffle
                                          (scalar_to_vector (loadf64 addr:$src)),
                                              (undef),
-                                            SSE_splat_v2_mask)))]>;
+                                            SSE_splat_lo_mask)))]>;
 
 // SSE2 instructions without OpSize prefix
 def Int_CVTDQ2PSrr : I<0x5B, MRMSrcReg, (ops VR128:$dst, VR128:$src),
@@ -1908,10 +1908,14 @@ def : Pat<(v4f32 (vector_shuffle immAllZerosV,
 
 // Splat v2f64 / v2i64
 let AddedComplexity = 10 in {
-def : Pat<(vector_shuffle (v2f64 VR128:$src), (undef), SSE_splat_v2_mask:$sm),
+def : Pat<(vector_shuffle (v2f64 VR128:$src), (undef), SSE_splat_lo_mask:$sm),
           (UNPCKLPDrr VR128:$src, VR128:$src)>,   Requires<[HasSSE2]>;
-def : Pat<(vector_shuffle (v2i64 VR128:$src), (undef), SSE_splat_v2_mask:$sm),
+def : Pat<(vector_shuffle (v2f64 VR128:$src), (undef), UNPCKH_shuffle_mask:$sm),
+          (UNPCKHPDrr VR128:$src, VR128:$src)>,   Requires<[HasSSE2]>;
+def : Pat<(vector_shuffle (v2i64 VR128:$src), (undef), SSE_splat_lo_mask:$sm),
           (PUNPCKLQDQrr VR128:$src, VR128:$src)>, Requires<[HasSSE2]>;
+def : Pat<(vector_shuffle (v2i64 VR128:$src), (undef), UNPCKH_shuffle_mask:$sm),
+          (PUNPCKHQDQrr VR128:$src, VR128:$src)>, Requires<[HasSSE2]>;
 }
 
 // Splat v4f32