[NVPTX] Add more precise PTX/SM target attributes

Each SM and PTX version is modeled as a subtarget feature/CPU. Additionally,
PTX 3.1 is added as the default PTX version to be out-of-the-box compatible
with CUDA 5.0.

Available CPUs for this target:

  sm_10 - Select the sm_10 processor.
  sm_11 - Select the sm_11 processor.
  sm_12 - Select the sm_12 processor.
  sm_13 - Select the sm_13 processor.
  sm_20 - Select the sm_20 processor.
  sm_21 - Select the sm_21 processor.
  sm_30 - Select the sm_30 processor.
  sm_35 - Select the sm_35 processor.

Available features for this target:

  ptx30 - Use PTX version 3.0.
  ptx31 - Use PTX version 3.1.
  sm_10 - Target SM 1.0.
  sm_11 - Target SM 1.1.
  sm_12 - Target SM 1.2.
  sm_13 - Target SM 1.3.
  sm_20 - Target SM 2.0.
  sm_21 - Target SM 2.1.
  sm_30 - Target SM 3.0.
  sm_35 - Target SM 3.5.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167699 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 6 deletions

diff --git a/lib/Target/NVPTX/NVPTXSubtarget.cpp b/lib/Target/NVPTX/NVPTXSubtarget.cpp
index 6aadd43e94..7b62cce2c6 100644
--- a/lib/Target/NVPTX/NVPTXSubtarget.cpp
+++ b/lib/Target/NVPTX/NVPTXSubtarget.cpp
@@ -34,16 +34,18 @@ DriverInterface(cl::desc("Choose driver interface:"),
 
 NVPTXSubtarget::NVPTXSubtarget(const std::string &TT, const std::string &CPU,
                                const std::string &FS, bool is64Bit)
-:NVPTXGenSubtargetInfo(TT, "", FS), // Don't pass CPU to subtarget,
- // because we don't register all
- // nvptx targets.
- Is64Bit(is64Bit) {
+: NVPTXGenSubtargetInfo(TT, CPU, FS),
+  Is64Bit(is64Bit),
+  PTXVersion(0),
+  SmVersion(10) {
 
   drvInterface = DriverInterface;
 
   // Provide the default CPU if none
   std::string defCPU = "sm_10";
 
+  ParseSubtargetFeatures((CPU.empty() ? defCPU : CPU), FS);
+
   // Get the TargetName from the FS if available
   if (FS.empty() && CPU.empty())
     TargetName = defCPU;
@@ -52,6 +54,12 @@ NVPTXSubtarget::NVPTXSubtarget(const std::string &TT, const std::string &CPU,
   else
     llvm_unreachable("we are not using FeatureStr");
 
-  // Set up the SmVersion
-  SmVersion = atoi(TargetName.c_str()+3);
+  // We default to PTX 3.1, but we cannot just default to it in the initializer
+  // since the attribute parser checks if the given option is >= the default.
+  // So if we set ptx31 as the default, the ptx30 attribute would never match.
+  // Instead, we use 0 as the default and manually set 31 if the default is
+  // used.
+  if (PTXVersion == 0) {
+    PTXVersion = 31;
+  }
 }