AMDGPU: Add subtarget feature for instruction rates

llvm-svn: 258085

4 files changed, 23 insertions, 9 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPU.td b/llvm/lib/Target/AMDGPU/AMDGPU.td
index 789187be2df..83ab1e80030 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPU.td
+++ b/llvm/lib/Target/AMDGPU/AMDGPU.td
@@ -59,6 +59,12 @@ def FeatureFastFMAF32 : SubtargetFeature<"fast-fmaf",
         "Assuming f32 fma is at least as fast as mul + add",
         []>;
 
+def HalfRate64Ops : SubtargetFeature<"half-rate-64-ops",
+        "HalfRate64Ops",
+        "true",
+        "Most fp64 instructions are half rate instead of quarter",
+        []>;
+
 // Some instructions do not support denormals despite this flag. Using
 // fp32 denormals also causes instructions to run at the double
 // precision rate for the device.
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.cpp b/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.cpp
index c6af5b93d25..d17a7ac2f3d 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.cpp
@@ -70,11 +70,14 @@ AMDGPUSubtarget::AMDGPUSubtarget(const Triple &TT, StringRef GPU, StringRef FS,
       DumpCode(false), R600ALUInst(false), HasVertexCache(false),
       TexVTXClauseSize(0), Gen(AMDGPUSubtarget::R600), FP64(false),
       FP64Denormals(false), FP32Denormals(false), FastFMAF32(false),
-      CaymanISA(false), FlatAddressSpace(false), FlatForGlobal(false),
-      EnableIRStructurizer(true), EnablePromoteAlloca(false), EnableIfCvt(true),
-      EnableLoadStoreOpt(false), EnableUnsafeDSOffsetFolding(false),
+      HalfRate64Ops(false), CaymanISA(false), FlatAddressSpace(false),
+      FlatForGlobal(false), EnableIRStructurizer(true),
+      EnablePromoteAlloca(false),
+      EnableIfCvt(true), EnableLoadStoreOpt(false),
+      EnableUnsafeDSOffsetFolding(false),
       EnableXNACK(false),
-      WavefrontSize(0), CFALUBug(false), LocalMemorySize(0),
+      WavefrontSize(0), CFALUBug(false),
+      LocalMemorySize(0),
       EnableVGPRSpilling(false), SGPRInitBug(false), IsGCN(false),
       GCN1Encoding(false), GCN3Encoding(false), CIInsts(false), LDSBankCount(0),
       IsaVersion(ISAVersion0_0_0), EnableHugeScratchBuffer(false),
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.h b/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.h
index f43ce40212a..3a4266947b4 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPUSubtarget.h
@@ -69,6 +69,7 @@ private:
   bool FP64Denormals;
   bool FP32Denormals;
   bool FastFMAF32;
+  bool HalfRate64Ops;
   bool CaymanISA;
   bool FlatAddressSpace;
   bool FlatForGlobal;
@@ -158,6 +159,10 @@ public:
     return FastFMAF32;
   }
 
+  bool hasHalfRate64Ops() const {
+    return HalfRate64Ops;
+  }
+
   bool hasFlatAddressSpace() const {
     return FlatAddressSpace;
   }
diff --git a/llvm/lib/Target/AMDGPU/Processors.td b/llvm/lib/Target/AMDGPU/Processors.td
index 9eaeb58b9b4..24681ea0da5 100644
--- a/llvm/lib/Target/AMDGPU/Processors.td
+++ b/llvm/lib/Target/AMDGPU/Processors.td
@@ -84,11 +84,11 @@ def : Proc<"cayman",     R600_VLIW4_Itin,
 //===----------------------------------------------------------------------===//
 
 def : ProcessorModel<"SI", SIFullSpeedModel,
-  [FeatureSouthernIslands, FeatureFastFMAF32]
+  [FeatureSouthernIslands, FeatureFastFMAF32, HalfRate64Ops]
 >;
 
-def : ProcessorModel<"tahiti",   SIFullSpeedModel,
-  [FeatureSouthernIslands, FeatureFastFMAF32]
+def : ProcessorModel<"tahiti", SIFullSpeedModel,
+  [FeatureSouthernIslands, FeatureFastFMAF32, HalfRate64Ops]
 >;
 
 def : ProcessorModel<"pitcairn", SIQuarterSpeedModel, [FeatureSouthernIslands]>;
@@ -116,8 +116,8 @@ def : ProcessorModel<"kaveri",     SIQuarterSpeedModel,
 >;
 
 def : ProcessorModel<"hawaii", SIFullSpeedModel,
-  [FeatureSeaIslands, FeatureFastFMAF32, FeatureLDSBankCount32,
-   FeatureISAVersion7_0_1]
+  [FeatureSeaIslands, FeatureFastFMAF32, HalfRate64Ops,
+   FeatureLDSBankCount32, FeatureISAVersion7_0_1]
 >;
 
 def : ProcessorModel<"mullins",    SIQuarterSpeedModel,