Power8 and later support fusing addis/addi and addis/ld instruction

pairs that use the same register to execute as a single instruction.
No Functional Change

Patch by Kyle Butt!

llvm-svn: 253724

3 files changed, 7 insertions, 1 deletions

diff --git a/llvm/lib/Target/PowerPC/PPC.td b/llvm/lib/Target/PowerPC/PPC.td
index f50100e7a8a..0f990dc64f9 100644
--- a/llvm/lib/Target/PowerPC/PPC.td
+++ b/llvm/lib/Target/PowerPC/PPC.td
@@ -137,6 +137,8 @@ def FeatureHTM : SubtargetFeature<"htm", "HasHTM", "true",
                                   "Enable Hardware Transactional Memory instructions">;
 def FeatureMFTB   : SubtargetFeature<"", "FeatureMFTB", "true",
                                         "Implement mftb using the mfspr instruction">;
+def FeatureFusion : SubtargetFeature<"fusion", "HasFusion", "true",
+                                     "Target supports add/load integer fusion.">;
 
 def DeprecatedDST    : SubtargetFeature<"", "DeprecatedDST", "true",
   "Treat vector data stream cache control instructions as deprecated">;
@@ -168,7 +170,8 @@ def ProcessorFeatures {
        FeatureMFTB, DeprecatedDST];
   list<SubtargetFeature> Power8SpecificFeatures =
       [DirectivePwr8, FeatureP8Altivec, FeatureP8Vector, FeatureP8Crypto,
-       FeatureHTM, FeatureDirectMove, FeatureICBT, FeaturePartwordAtomic];
+       FeatureHTM, FeatureDirectMove, FeatureICBT, FeaturePartwordAtomic,
+       FeatureFusion];
   list<SubtargetFeature> Power8FeatureList =
       !listconcat(Power7FeatureList, Power8SpecificFeatures);
 }
diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
index 9a9bdfdad00..27d51f266ef 100644
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
@@ -100,6 +100,7 @@ void PPCSubtarget::initializeEnvironment() {
   HasDirectMove = false;
   IsQPXStackUnaligned = false;
   HasHTM = false;
+  HasFusion = false;
 }
 
 void PPCSubtarget::initSubtargetFeatures(StringRef CPU, StringRef FS) {
diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.h b/llvm/lib/Target/PowerPC/PPCSubtarget.h
index b21931b1b2d..105ceae4e36 100644
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.h
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.h
@@ -119,6 +119,7 @@ protected:
   bool HasPartwordAtomics;
   bool HasDirectMove;
   bool HasHTM;
+  bool HasFusion;
 
   /// When targeting QPX running a stock PPC64 Linux kernel where the stack
   /// alignment has not been changed, we need to keep the 16-byte alignment
@@ -254,6 +255,7 @@ public:
     return 16;
   }
   bool hasHTM() const { return HasHTM; }
+  bool hasFusion() const { return HasFusion; }
 
   const Triple &getTargetTriple() const { return TargetTriple; }