fix asm casts of float as ffi params

2 files changed, 11 insertions, 8 deletions

diff --git a/lib/Target/JSBackend/CallHandlers.h b/lib/Target/JSBackend/CallHandlers.h
index 8c97459375..d3b3dfa668 100644
--- a/lib/Target/JSBackend/CallHandlers.h
+++ b/lib/Target/JSBackend/CallHandlers.h
@@ -80,11 +80,14 @@ DEF_CALL_HANDLER(__default__, {
     }
     if (NumArgs > 0) text += ",";
   }
+  // this is an ffi call if we need casts, and it is not a Math_ builtin
+  bool FFI = NeedCasts && Name.find("Math_") != 0;
+  unsigned FFI_OUT = FFI ? ASM_FFI_OUT : 0;
   for (int i = 0; i < NumArgs; i++) {
     if (!NeedCasts) {
       text += getValueAsStr(CI->getOperand(i));
     } else {
-      text += getValueAsCastStr(CI->getOperand(i), ASM_NONSPECIFIC);
+      text += getValueAsCastStr(CI->getOperand(i), ASM_NONSPECIFIC | FFI_OUT);
     }
     if (i < NumArgs - 1) text += ",";
   }
@@ -98,9 +101,8 @@ DEF_CALL_HANDLER(__default__, {
     getAssign(getJSName(CI), InstRT); // ensure the variable is defined, but do not emit it here
                                       // it should have 0 uses, but just to be safe
   } else if (!ActualRT->isVoidTy()) {
-    // this is an ffi call if we need casts, and it is not a Math_ builtin
-    unsigned FFI = NeedCasts && text.find("Math_") != 0 ? ASM_FFI : 0;
-    text = getAssign(getJSName(CI), ActualRT) + getCast(text, ActualRT, ASM_NONSPECIFIC | FFI);
+    unsigned FFI_IN = FFI ? ASM_FFI_IN : 0;
+    text = getAssign(getJSName(CI), ActualRT) + getCast(text, ActualRT, ASM_NONSPECIFIC | FFI_IN);
   }
   return text;
 })
diff --git a/lib/Target/JSBackend/JSBackend.cpp b/lib/Target/JSBackend/JSBackend.cpp
index 2a622c81f3..3345affcbb 100644
--- a/lib/Target/JSBackend/JSBackend.cpp
+++ b/lib/Target/JSBackend/JSBackend.cpp
@@ -75,7 +75,8 @@ namespace {
   #define ASM_SIGNED 0
   #define ASM_UNSIGNED 1
   #define ASM_NONSPECIFIC 2 // nonspecific means to not differentiate ints. |0 for all, regardless of size and sign
-  #define ASM_FFI 4 // FFI values are limited to things that work in ffis
+  #define ASM_FFI_IN 4 // FFI return values are limited to things that work in ffis
+  #define ASM_FFI_OUT 8 // params to FFIs are limited to things that work in ffis
   typedef unsigned AsmCast;
 
   const char *SIMDLane = "XYZW";
@@ -474,8 +475,8 @@ std::string JSWriter::getCast(const StringRef &s, const Type *t, AsmCast sign) {
       if (!t->isVectorTy()) assert(false && "Unsupported type");
     }
     case Type::FloatTyID: {
-      if (PreciseF32) {
-        if (sign & ASM_FFI) {
+      if (PreciseF32 && !(sign & ASM_FFI_OUT)) {
+        if (sign & ASM_FFI_IN) {
           return ("Math_fround(+(" + s + "))").str();
         } else {
           return ("Math_fround(" + s + ")").str();
@@ -816,7 +817,7 @@ std::string JSWriter::getConstant(const Constant* CV, AsmCast sign) {
   } else {
     if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
       std::string S = ftostr_exact(CFP);
-      if (PreciseF32 && CV->getType()->isFloatTy()) {
+      if (PreciseF32 && CV->getType()->isFloatTy() && !(sign & ASM_FFI_OUT)) {
         S = "Math_fround(" + S + ")";
       } else if (S[0] != '+') {
         S = '+' + S;