unfinished work

ldc-developers · Apr 23, 2016 · e81cefd · e81cefd
1 parent 9e80617
commit e81cefd
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Showing 3 changed files with 38 additions and 59 deletions.
diff --git a/gen/ldctraits.cpp b/gen/ldctraits.cpp
@@ -9,6 +9,8 @@
 
 #include "gen/irstate.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include <iostream>
 
 // TODO: move this to a D interfacing helper file
 struct Dstring {
@@ -21,7 +23,14 @@ Dstring traitsGetTargetCPU() {
   return {cpu.data(), cpu.size()};
 }
 
-Dstring traitsGetTargetFeatures() {
-  auto features = gTargetMachine->getTargetFeatureString();
-  return {features.data(), features.size()};
+bool traitsTargetHasFeature(Dstring feature) {
+  auto feat = llvm::StringRef(feature.ptr, feature.len);
+
+  auto *mcinfo = const_cast<llvm::MCSubtargetInfo*>( gTargetMachine->getMCSubtargetInfo() );
+  auto savedFeatbits = mcinfo->getFeatureBits();
+  auto newFeatbits = mcinfo->ApplyFeatureFlag(feat);
+  bool featureFound = (savedFeatbits == newFeatbits);
+  mcinfo->setFeatureBits(savedFeatbits);
+
+  return featureFound;
 }
diff --git a/gen/ldctraits.d b/gen/ldctraits.d
@@ -29,36 +29,7 @@ extern(C++) struct Dstring
 };
 
 extern(C++) Dstring traitsGetTargetCPU();
-extern(C++) Dstring traitsGetTargetFeatures();
-
-// Parses the comma separated features into a (positive-only) array of feature strings
-private const(char)[][] traitsGetTargetFeaturesArray()
-{
-    auto llvmfeatures = traitsGetTargetFeatures();
-
-    const(char)[][] result;
-    size_t pos;
-    while (pos < llvmfeatures.len)
-    {
-        // Find out whether this is a positive or negative feature
-        bool positive = llvmfeatures.ptr[pos++] == '+';
-        size_t start = pos;
-        // Walk to the next comma or end-of-string
-        while (pos < llvmfeatures.len)
-        {
-            if (llvmfeatures.ptr[pos] == ',')
-                break;
-            pos++;
-        }
-        if (positive)
-        {
-            result ~= llvmfeatures.ptr[start..pos];
-        }
-        pos++;
-    }
-
-    return result;
-}
+extern(C++) bool traitsTargetHasFeature(Dstring feature);
 
 Expression semanticTraitsLDC(TraitsExp e, Scope* sc)
 {
@@ -75,22 +46,6 @@ Expression semanticTraitsLDC(TraitsExp e, Scope* sc)
         auto se = new StringExp(e.loc, cast(void*)cpu.ptr, cpu.len);
         return se.semantic(sc);
     }
-    if (e.ident == Id.targetFeatures)
-    {
-        if (arg_count != 0)
-        {
-            e.warning("ignoring arguments for __traits %s", e.ident.toChars());
-        }
-
-        auto features = traitsGetTargetFeaturesArray();
-        auto exps = new Expressions();
-        foreach(feat; features)
-        {
-            exps.push(new StringExp(e.loc, cast(void*)feat.ptr, feat.length));
-        }
-        auto tup = new TupleExp(e.loc, exps);
-        return tup.semantic(sc);
-    }
     if (e.ident == Id.targetHasFeature)
     {
         if (arg_count != 1)
@@ -120,16 +75,8 @@ Expression semanticTraitsLDC(TraitsExp e, Scope* sc)
             return new ErrorExp();
         }
 
-        auto searchfor = se.string[0..se.len];
-
-        auto features = traitsGetTargetFeaturesArray();
-        foreach(feat; features)
-        {
-            if (feat == searchfor)
-                return new IntegerExp(e.loc, 1, Type.tbool);
-        }
-        // Feature not found
-        return new IntegerExp(e.loc, 0, Type.tbool);
+        auto featureFound = traitsTargetHasFeature(Dstring(se.toPtr(), se.len));
+        return new IntegerExp(e.loc, featureFound ? 1 : 0, Type.tbool);
     }
     return null;
 }
diff --git a/tests/codegen/target_traits.d b/tests/codegen/target_traits.d
@@ -0,0 +1,23 @@
+// Tests LDC-specific target __traits
+
+// RUN: %ldc -mcpu="haswell" -mattr="-sse" -c %s
+
+import std.algorithm;
+import std.stdio;
+
+void main()
+{
+  /*  static assert(__traits(targetCPU) == "haswell");
+    static assert(!__traits(targetHasFeature, "sse"));
+    static assert(__traits(targetHasFeature, "sse3"));
+    static assert(__traits(targetHasFeature, "sse4.1"));
+    static assert(!__traits(targetHasFeature, "sse4"));
+    static assert(!__traits(targetHasFeature, "sse4a"));
+    static assert(any!q{a = "sse4.1"}([__traits(targetFeatures)]));
+*/
+    writeln("CPU = ", __traits(targetCPU));
+//    writeln("Features = ", [__traits(targetFeatures)]);
+//    writeln("Has 'sse3' = ", __traits(targetHasFeature, "sse3"));
+    writeln("Has 'sse4' = ", __traits(targetHasFeature, "sse4"));
+  //  writeln("Has 'sse4.1' = ", any!q{a = "sse4.1"}([__traits(targetFeatures)]));
+}