Use LLVM to detect CPU features by default if --features aren't speci…

…fied.
ponylang · Feb 14, 2017 · ca17f03 · ca17f03
1 parent ce25599
commit ca17f03
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Showing 4 changed files with 34 additions and 1 deletion.
diff --git a/src/libponyc/codegen/codegen.c b/src/libponyc/codegen/codegen.c
@@ -882,7 +882,7 @@ bool codegen_init(pass_opt_t* opt)
   if(opt->features != NULL)
     opt->features = LLVMCreateMessage(opt->features);
   else
-    opt->features = LLVMCreateMessage("");
+    opt->features = LLVMGetHostCPUFeatures();
 
   return true;
 }

diff --git a/src/libponyc/codegen/codegen.h b/src/libponyc/codegen/codegen.h
@@ -21,6 +21,7 @@ PONY_EXTERN_C_BEGIN
 
 // Missing from C API.
 char* LLVMGetHostCPUName();
+char* LLVMGetHostCPUFeatures();
 void LLVMSetUnsafeAlgebra(LLVMValueRef inst);
 void LLVMSetNoUnsignedWrap(LLVMValueRef inst);
 void LLVMSetNoSignedWrap(LLVMValueRef inst);

diff --git a/src/libponyc/codegen/host.cc b/src/libponyc/codegen/host.cc
@@ -33,6 +33,37 @@ char* LLVMGetHostCPUName()
   return strdup(sys::getHostCPUName().str().c_str());
 }
 
+char* LLVMGetHostCPUFeatures()
+{
+  StringMap<bool> features;
+  assert(sys::getHostCPUFeatures(features));
+
+  // Calculate the size of buffer that will be needed to return all features.
+  size_t buf_size = 0;
+  for(auto it = features.begin(); it != features.end(); it++)
+    buf_size += (*it).getKey().str().length() + 2; // plus +/- char and ,/null
+
+  char* buf = (char*)malloc(buf_size);
+  assert(buf != NULL);
+  buf[0] = 0;
+
+  for(auto it = features.begin(); it != features.end();)
+  {
+    if((*it).getValue())
+      strcat(buf, "+");
+    else
+      strcat(buf, "-");
+
+    strcat(buf, (*it).getKey().str().c_str());
+
+    it++;
+    if(it != features.end())
+      strcat(buf, ",");
+  }
+
+  return buf;
+}
+
 void LLVMSetUnsafeAlgebra(LLVMValueRef inst)
 {
   unwrap<Instruction>(inst)->setHasUnsafeAlgebra(true);

diff --git a/src/ponyc/main.c b/src/ponyc/main.c
@@ -125,6 +125,7 @@ static void usage()
     "    =name         Default is the host CPU.\n"
     "  --features      CPU features to enable or disable.\n"
     "    =+this,-that  Use + to enable, - to disable.\n"
+    "                  Defaults to detecting all CPU features from the host.\n"
     "  --triple        Set the target triple.\n"
     "    =name         Defaults to the host triple.\n"
     "  --stats         Print some compiler stats.\n"