[llvm-commits] [llvm] r126080 - in /llvm/trunk: docs/LangRef.html lib/CodeGen/SelectionDAG/DAGCombiner.cpp test/CodeGen/X86/vec_zext.ll

[Nadav Rotem]

Author: nadav
Date: Sun Feb 20 06:37:50 2011
New Revision: 126080

URL: http://llvm.org/viewvc/llvm-project?rev=126080&view=rev
Log:
Fix 9267;  Add vector zext support.

The DAGCombiner folds the zext into complex load instructions. This patch
prevents this optimization on vectors since none of the supported targets
knows how to perform load+vector_zext in one instruction.


Added:
    llvm/trunk/test/CodeGen/X86/vec_zext.ll
Modified:
    llvm/trunk/docs/LangRef.html
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Modified: llvm/trunk/docs/LangRef.html
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/LangRef.html?rev=126080&r1=126079&r2=126080&view=diff
==============================================================================
--- llvm/trunk/docs/LangRef.html (original)
+++ llvm/trunk/docs/LangRef.html Sun Feb 20 06:37:50 2011
@@ -4614,10 +4614,11 @@
 
 
 <h5>Arguments:</h5>
-<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
-   <a href="#t_integer">integer</a> type, and a type to cast it to, which must
-   also be of <a href="#t_integer">integer</a> type. The bit size of the
-   <tt>value</tt> must be smaller than the bit size of the destination type,
+<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
+   Both types must be of <a href="#t_integer">integer</a> types, or vectors
+   of the same number of integers.
+   The bit size of the <tt>value</tt> must be smaller than
+   the bit size of the destination type,
    <tt>ty2</tt>.</p>
 
 <h5>Semantics:</h5>
@@ -4630,6 +4631,7 @@
 <pre>
   %X = zext i32 257 to i64              <i>; yields i64:257</i>
   %Y = zext i1 true to i32              <i>; yields i32:1</i>
+  %Z = zext <2 x i16> <i16 8, i16 7> to <2 x i32> <i>; yields <i32 8, i32 7></i>
 </pre>
 
 </div>

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=126080&r1=126079&r2=126080&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Sun Feb 20 06:37:50 2011
@@ -3887,7 +3887,9 @@
   }
 
   // fold (zext (load x)) -> (zext (truncate (zextload x)))
-  if (ISD::isNON_EXTLoad(N0.getNode()) &&
+  // None of the supported targets knows how to perform load and vector_zext
+  // in one instruction.  We only perform this transformation on scalar zext.
+  if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
       ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
        TLI.isLoadExtLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
     bool DoXform = true;

Added: llvm/trunk/test/CodeGen/X86/vec_zext.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vec_zext.ll?rev=126080&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vec_zext.ll (added)
+++ llvm/trunk/test/CodeGen/X86/vec_zext.ll Sun Feb 20 06:37:50 2011
@@ -0,0 +1,69 @@
+; RUN: llc < %s -march=x86-64
+; PR 9267
+
+define<4 x i32> @func_16_32() {
+  %F = load <4 x i16>* undef
+  %G = zext <4 x i16> %F to <4 x i32>
+  %H = load <4 x i16>* undef
+  %Y = zext <4 x i16> %H to <4 x i32>
+  %T = add <4 x i32> %Y, %G
+  store <4 x i32>%T , <4 x i32>* undef
+  ret <4 x i32> %T
+}
+
+define<4 x i64> @func_16_64() {
+  %F = load <4 x i16>* undef
+  %G = zext <4 x i16> %F to <4 x i64>
+  %H = load <4 x i16>* undef
+  %Y = zext <4 x i16> %H to <4 x i64>
+  %T = xor <4 x i64> %Y, %G
+  store <4 x i64>%T , <4 x i64>* undef
+  ret <4 x i64> %T
+}
+
+define<4 x i64> @func_32_64() {
+  %F = load <4 x i32>* undef
+  %G = zext <4 x i32> %F to <4 x i64>
+  %H = load <4 x i32>* undef
+  %Y = zext <4 x i32> %H to <4 x i64>
+  %T = or <4 x i64> %Y, %G
+  ret <4 x i64> %T
+}
+
+define<4 x i16> @func_8_16() {
+  %F = load <4 x i8>* undef
+  %G = zext <4 x i8> %F to <4 x i16>
+  %H = load <4 x i8>* undef
+  %Y = zext <4 x i8> %H to <4 x i16>
+  %T = add <4 x i16> %Y, %G
+  ret <4 x i16> %T
+}
+
+define<4 x i32> @func_8_32() {
+  %F = load <4 x i8>* undef
+  %G = zext <4 x i8> %F to <4 x i32>
+  %H = load <4 x i8>* undef
+  %Y = zext <4 x i8> %H to <4 x i32>
+  %T = sub <4 x i32> %Y, %G
+  ret <4 x i32> %T
+}
+
+define<4 x i64> @func_8_64() {
+  %F = load <4 x i8>* undef
+  %G = zext <4 x i8> %F to <4 x i64>
+  %H = load <4 x i8>* undef
+  %Y = zext <4 x i8> %H to <4 x i64>
+  %T = add <4 x i64> %Y, %G
+  ret <4 x i64> %T
+}
+
+define<4 x i32> @const_16_32() {
+  %G = zext <4 x i16> <i16 0, i16 3, i16 8, i16 7> to <4 x i32>
+  ret <4 x i32> %G
+}
+
+define<4 x i64> @const_16_64() {
+  %G = zext <4 x i16> <i16 0, i16 3, i16 8, i16 7> to <4 x i64>
+  ret <4 x i64> %G
+}
+