Move x86 specific shuffle mask decoding to its own header, it's also going to be used elsewhere. Also trim trailing whitespaces

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112846 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 145 insertions, 0 deletions

diff --git a/lib/Target/X86/X86ShuffleDecode.h b/lib/Target/X86/X86ShuffleDecode.h
new file mode 100644
index 0000000..4d24c83
--- /dev/null
+++ b/lib/Target/X86/X86ShuffleDecode.h
@@ -0,0 +1,145 @@
+//===-- X86ShuffleDecode.h - X86 shuffle decode logic ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Define several functions to decode x86 specific shuffle semantics into a
+// generic vector mask.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef X86_SHUFFLE_DECODE_H
+#define X86_SHUFFLE_DECODE_H
+
+#include "llvm/ADT/SmallVector.h"
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+//  Vector Mask Decoding
+//===----------------------------------------------------------------------===//
+
+enum {
+  SM_SentinelZero = ~0U
+};
+
+static void DecodeINSERTPSMask(unsigned Imm,
+                               SmallVectorImpl<unsigned> &ShuffleMask) {
+  // Defaults the copying the dest value.
+  ShuffleMask.push_back(0);
+  ShuffleMask.push_back(1);
+  ShuffleMask.push_back(2);
+  ShuffleMask.push_back(3);
+
+  // Decode the immediate.
+  unsigned ZMask = Imm & 15;
+  unsigned CountD = (Imm >> 4) & 3;
+  unsigned CountS = (Imm >> 6) & 3;
+
+  // CountS selects which input element to use.
+  unsigned InVal = 4+CountS;
+  // CountD specifies which element of destination to update.
+  ShuffleMask[CountD] = InVal;
+  // ZMask zaps values, potentially overriding the CountD elt.
+  if (ZMask & 1) ShuffleMask[0] = SM_SentinelZero;
+  if (ZMask & 2) ShuffleMask[1] = SM_SentinelZero;
+  if (ZMask & 4) ShuffleMask[2] = SM_SentinelZero;
+  if (ZMask & 8) ShuffleMask[3] = SM_SentinelZero;
+}
+
+static void DecodeMOVHLPSMask(SmallVectorImpl<unsigned> &ShuffleMask) {
+  ShuffleMask.push_back(3);
+  ShuffleMask.push_back(1);
+}
+
+static void DecodeMOVLHPSMask(SmallVectorImpl<unsigned> &ShuffleMask) {
+  ShuffleMask.push_back(0);
+  ShuffleMask.push_back(2);
+}
+
+static void DecodePSHUFMask(unsigned NElts, unsigned Imm,
+                            SmallVectorImpl<unsigned> &ShuffleMask) {
+  for (unsigned i = 0; i != NElts; ++i) {
+    ShuffleMask.push_back(Imm % NElts);
+    Imm /= NElts;
+  }
+}
+
+static void DecodePSHUFHWMask(unsigned Imm,
+                              SmallVectorImpl<unsigned> &ShuffleMask) {
+  ShuffleMask.push_back(0);
+  ShuffleMask.push_back(1);
+  ShuffleMask.push_back(2);
+  ShuffleMask.push_back(3);
+  for (unsigned i = 0; i != 4; ++i) {
+    ShuffleMask.push_back(4+(Imm & 3));
+    Imm >>= 2;
+  }
+}
+
+static void DecodePSHUFLWMask(unsigned Imm,
+                              SmallVectorImpl<unsigned> &ShuffleMask) {
+  for (unsigned i = 0; i != 4; ++i) {
+    ShuffleMask.push_back((Imm & 3));
+    Imm >>= 2;
+  }
+  ShuffleMask.push_back(4);
+  ShuffleMask.push_back(5);
+  ShuffleMask.push_back(6);
+  ShuffleMask.push_back(7);
+}
+
+static void DecodePUNPCKLMask(unsigned NElts,
+                              SmallVectorImpl<unsigned> &ShuffleMask) {
+  for (unsigned i = 0; i != NElts/2; ++i) {
+    ShuffleMask.push_back(i);
+    ShuffleMask.push_back(i+NElts);
+  }
+}
+
+static void DecodePUNPCKHMask(unsigned NElts,
+                              SmallVectorImpl<unsigned> &ShuffleMask) {
+  for (unsigned i = 0; i != NElts/2; ++i) {
+    ShuffleMask.push_back(i+NElts/2);
+    ShuffleMask.push_back(i+NElts+NElts/2);
+  }
+}
+
+static void DecodeSHUFPSMask(unsigned NElts, unsigned Imm,
+                             SmallVectorImpl<unsigned> &ShuffleMask) {
+  // Part that reads from dest.
+  for (unsigned i = 0; i != NElts/2; ++i) {
+    ShuffleMask.push_back(Imm % NElts);
+    Imm /= NElts;
+  }
+  // Part that reads from src.
+  for (unsigned i = 0; i != NElts/2; ++i) {
+    ShuffleMask.push_back(Imm % NElts + NElts);
+    Imm /= NElts;
+  }
+}
+
+static void DecodeUNPCKHPMask(unsigned NElts,
+                              SmallVectorImpl<unsigned> &ShuffleMask) {
+  for (unsigned i = 0; i != NElts/2; ++i) {
+    ShuffleMask.push_back(i+NElts/2);        // Reads from dest
+    ShuffleMask.push_back(i+NElts+NElts/2);  // Reads from src
+  }
+}
+
+
+/// DecodeUNPCKLPMask - This decodes the shuffle masks for unpcklps/unpcklpd
+/// etc.  NElts indicates the number of elements in the vector allowing it to
+/// handle different datatypes and vector widths.
+static void DecodeUNPCKLPMask(unsigned NElts,
+                              SmallVectorImpl<unsigned> &ShuffleMask) {
+  for (unsigned i = 0; i != NElts/2; ++i) {
+    ShuffleMask.push_back(i);        // Reads from dest
+    ShuffleMask.push_back(i+NElts);  // Reads from src
+  }
+}
+
+#endif