Use builtins instead of shims in FloatingPointTypes. (#3454)

* Map .round, .squareRoot, .addProduct, and .formRemainder onto builtins instead of shims where possible.

Author: stephentyrone

lib/SIL/SILVerifier.cpp

@@ -3263,7 +3263,7 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
       assert(F->isAvailableExternally() &&
              "external declaration of internal SILFunction not allowed");
       assert(!hasSharedVisibility(F->getLinkage()) &&
-             "external declarations of SILFunctions with shared visibility is not "
+             "external declaration of SILFunction with shared visibility is not "
              "allowed");
       // If F is an external declaration, there is nothing further to do,
       // return.

stdlib/public/SwiftShims/LibcShims.h

@@ -83,48 +83,67 @@ SWIFT_RUNTIME_STDLIB_INTERFACE
 __swift_uint32_t
 _swift_stdlib_cxx11_mt19937_uniform(__swift_uint32_t upper_bound);
 
-// Math library functions
-SWIFT_RUNTIME_STDLIB_INTERFACE float _swift_stdlib_remainderf(float, float);
-SWIFT_RUNTIME_STDLIB_INTERFACE float _swift_stdlib_squareRootf(float);
+#if defined __APPLE__
+static inline float _swift_stdlib_remainderf(float x, float y) {
+  return __builtin_remainderf(x, y);
+}
+
+static inline float _swift_stdlib_sqrtf(float x) {
+  return __builtin_sqrtf(x);
+}
+
+static inline double _swift_stdlib_remainder(double x, double y) {
+  return __builtin_remainder(x, y);
+}
+
+static inline double _swift_stdlib_sqrt(double x) {
+  return __builtin_sqrt(x);
+}
+
+# if defined __i386__ || defined __x86_64__
+// We use void* for these because the importer doesn't know how to map Float80
+// to long double.
+static inline void _swift_stdlib_remainderl(void *x, const void *y) {
+  long double *ptr = (long double *)x;
+  *ptr = __builtin_remainderl(*ptr, *(const long double *)y);
+}
+
+static inline void _swift_stdlib_sqrtl(void *x) {
+  long double *ptr = (long double *)x;
+  *ptr = __builtin_sqrtl(*ptr);
+}
+# endif // defined __i386__ || defined __x86_64__
+#else
+// We want the math shims to be static inline for performance reasons, but
+// that causes test failures on Linux at present, and depends on a compiler
+// feature (__builtin_xxxx) that may not be available on other platforms.
+// They are therefore declared as SWIFT_RUNTIME_STDLIB_INTERFACE functions
+// on non-Apple platforms for now.
 SWIFT_RUNTIME_STDLIB_INTERFACE
-float _swift_stdlib_addProductf(float, float, float);
-SWIFT_RUNTIME_STDLIB_INTERFACE float _swift_stdlib_roundf(float);
-SWIFT_RUNTIME_STDLIB_INTERFACE float _swift_stdlib_roundevenf(float);
-SWIFT_RUNTIME_STDLIB_INTERFACE float _swift_stdlib_truncf(float);
-SWIFT_RUNTIME_STDLIB_INTERFACE float _swift_stdlib_roundawayf(float);
-SWIFT_RUNTIME_STDLIB_INTERFACE float _swift_stdlib_ceilf(float);
-SWIFT_RUNTIME_STDLIB_INTERFACE float _swift_stdlib_floorf(float);
-  
-SWIFT_RUNTIME_STDLIB_INTERFACE double _swift_stdlib_remainder(double, double);
-SWIFT_RUNTIME_STDLIB_INTERFACE double _swift_stdlib_squareRoot(double);
+float _swift_stdlib_remainderf(float x, float y);
+ 
 SWIFT_RUNTIME_STDLIB_INTERFACE
-double _swift_stdlib_addProduct(double, double, double);
-SWIFT_RUNTIME_STDLIB_INTERFACE double _swift_stdlib_round(double);
-SWIFT_RUNTIME_STDLIB_INTERFACE double _swift_stdlib_roundeven(double);
-SWIFT_RUNTIME_STDLIB_INTERFACE double _swift_stdlib_trunc(double);
-SWIFT_RUNTIME_STDLIB_INTERFACE double _swift_stdlib_roundaway(double);
-SWIFT_RUNTIME_STDLIB_INTERFACE double _swift_stdlib_ceil(double);
-SWIFT_RUNTIME_STDLIB_INTERFACE double _swift_stdlib_floor(double);
-  
-// TODO: Remove horrible workaround when importer does Float80 <-> long double.
-#if (defined __i386__ || defined __x86_64__) && !defined _MSC_VER
+float _swift_stdlib_sqrtf(float x);
+
 SWIFT_RUNTIME_STDLIB_INTERFACE
-void _swift_stdlib_remainderl(void *_self, const void *_other);
+double _swift_stdlib_remainder(double x, double y);
+
 SWIFT_RUNTIME_STDLIB_INTERFACE
-void _swift_stdlib_squareRootl(void *_self);
+double _swift_stdlib_sqrt(double x);
+
+# if (defined __i386__ || defined __x86_64__) && !defined _MSC_VER
+// We use void* for these because the importer doesn't know how to map Float80
+// to long double.
 SWIFT_RUNTIME_STDLIB_INTERFACE
-void _swift_stdlib_addProductl(void *_self, const void *_lhs, const void *_rhs);
-SWIFT_RUNTIME_STDLIB_INTERFACE void _swift_stdlib_roundl(void *_self);
-SWIFT_RUNTIME_STDLIB_INTERFACE void _swift_stdlib_roundevenl(void *_self);
-SWIFT_RUNTIME_STDLIB_INTERFACE void _swift_stdlib_truncl(void *_self);
-SWIFT_RUNTIME_STDLIB_INTERFACE void _swift_stdlib_roundawayl(void *_self);
-SWIFT_RUNTIME_STDLIB_INTERFACE void _swift_stdlib_ceill(void *_self);
-SWIFT_RUNTIME_STDLIB_INTERFACE void _swift_stdlib_floorl(void *_self);
+void _swift_stdlib_remainderl(void *x, const void *y);
+
+SWIFT_RUNTIME_STDLIB_INTERFACE
+void _swift_stdlib_sqrtl(void *x);
+# endif // defined __i386__ || defined __x86_64__
 #endif
 
 #ifdef __cplusplus
 }} // extern "C", namespace swift
 #endif
 
 #endif // SWIFT_STDLIB_SHIMS_LIBCSHIMS_H
-

stdlib/public/core/FloatingPointTypes.swift.gyb

@@ -510,37 +510,30 @@ extension ${Self}: BinaryFloatingPoint {
 
   @_transparent
   public mutating func round(_ rule: FloatingPointRoundingRule) {
-%if bits == 80:
     switch rule {
     case .toNearestOrAwayFromZero:
-      _swift_stdlib_roundl(&self)
+      _value = Builtin.int_round_FPIEEE${bits}(_value)
     case .toNearestOrEven:
-      _swift_stdlib_roundevenl(&self)
+      //  TODO: switch to roundeven( ) or corresponding builtin when
+      //  available; rint assumes default floating-point environment.
+      //  This is pretty OK at present, since there's no Swifty way
+      //  to fuss with the environment, but we should fix it in the
+      //  long term.
+      _value = Builtin.int_rint_FPIEEE${bits}(_value)
     case .towardZero:
-      _swift_stdlib_truncl(&self)
+      _value = Builtin.int_trunc_FPIEEE${bits}(_value)
     case .awayFromZero:
-      _swift_stdlib_roundawayl(&self)
-    case .up:
-      _swift_stdlib_ceill(&self)
-    case .down:
-      _swift_stdlib_floorl(&self)
-    }
-%else:
-    switch rule {
-    case .toNearestOrAwayFromZero:
-      self = _swift_stdlib_round${cFuncSuffix(bits)}(self)
-    case .toNearestOrEven:
-      self = _swift_stdlib_roundeven${cFuncSuffix(bits)}(self)
-    case .towardZero:
-      self = _swift_stdlib_trunc${cFuncSuffix(bits)}(self)
-    case .awayFromZero:
-      self = _swift_stdlib_roundaway${cFuncSuffix(bits)}(self)
+      if sign == .minus {
+        _value = Builtin.int_floor_FPIEEE${bits}(_value)
+      }
+      else {
+        _value = Builtin.int_ceil_FPIEEE${bits}(_value)
+      }
     case .up:
-      self = _swift_stdlib_ceil${cFuncSuffix(bits)}(self)
+      _value = Builtin.int_ceil_FPIEEE${bits}(_value)
     case .down:
-      self = _swift_stdlib_floor${cFuncSuffix(bits)}(self)
+      _value = Builtin.int_floor_FPIEEE${bits}(_value)
     }
-%end
   }
 
   @_transparent
@@ -586,21 +579,16 @@ extension ${Self}: BinaryFloatingPoint {
   @_transparent
   public mutating func formSquareRoot( ) {
 %if bits == 80:
-    _swift_stdlib_squareRootl(&self)
+    _swift_stdlib_sqrtl(&self)
 %else:
-    self = _swift_stdlib_squareRoot${cFuncSuffix(bits)}(self)
+    self = _swift_stdlib_sqrt${cFuncSuffix(bits)}(self)
 %end
+
   }
 
   @_transparent
   public mutating func addProduct(_ lhs: ${Self}, _ rhs: ${Self}) {
-%if bits == 80:
-    var lhs = lhs
-    var rhs = rhs
-    _swift_stdlib_addProductl(&self, &lhs, &rhs)
-%else:
-    self = _swift_stdlib_addProduct${cFuncSuffix(bits)}(self, lhs, rhs)
-%end
+    _value = Builtin.int_fma_FPIEEE${bits}(lhs._value, rhs._value, _value)
   }
 
   @_transparent

stdlib/public/stubs/LibcShims.cpp

@@ -125,104 +125,37 @@ swift::_swift_stdlib_cxx11_mt19937_uniform(__swift_uint32_t upper_bound) {
   return RandomUniform(getGlobalMT19937());
 }
 
-float swift::_swift_stdlib_remainderf(float dividend, float divisor) {
-  return std::remainder(dividend, divisor);
+#if !defined __APPLE__
+//  These functions are static inline on Apple platforms, and therefore
+//  function bodies are not needed here.  They should ideally be made static
+//  inlines on other platforms as well.
+float swift::_swift_stdlib_remainderf(float x, float y) {
+  return std::remainder(x, y);
 }
 
-float swift::_swift_stdlib_squareRootf(float x) { return std::sqrt(x); }
-
-float swift::_swift_stdlib_addProductf(float addend, float lhs, float rhs) {
-  return std::fma(lhs, rhs, addend);
-}
-
-float swift::_swift_stdlib_roundf(float x) { return std::round(x); }
-
-float swift::_swift_stdlib_roundevenf(float x) {
-  //  TODO: switch to roundevenf( ) when available in backing C libraries, or
-  //  open-code here to correctly handle non-default fenv.
-  return std::rint(x);
-}
-
-float swift::_swift_stdlib_truncf(float x) { return std::trunc(x); }
-
-float swift::_swift_stdlib_roundawayf(float x) {
-  //  No corresponding C function, but trivial to fake.
-  return x < 0 ? std::floor(x) : std::ceil(x);
-}
-
-float swift::_swift_stdlib_ceilf(float x) { return std::ceil(x); }
-
-float swift::_swift_stdlib_floorf(float x) { return std::floor(x); }
-
-double swift::_swift_stdlib_remainder(double dividend, double divisor) {
-  return std::remainder(dividend, divisor);
-}
-
-double swift::_swift_stdlib_squareRoot(double x) { return std::sqrt(x); }
-
-double swift::_swift_stdlib_addProduct(double addend, double lhs, double rhs) {
-  return std::fma(lhs, rhs, addend);
-}
-
-double swift::_swift_stdlib_round(double x) { return std::round(x); }
-
-double swift::_swift_stdlib_roundeven(double x) {
-  //  TODO: switch to roundevenf( ) when available in backing C libraries, or
-  //  open-code here to correctly handle non-default fenv.
-  return std::rint(x);
-}
-
-double swift::_swift_stdlib_trunc(double x) { return std::trunc(x); }
-
-double swift::_swift_stdlib_roundaway(double x) {
-  //  No corresponding C function, but trivial to fake.
-  return x < 0 ? std::floor(x) : std::ceil(x);
-}
-
-double swift::_swift_stdlib_ceil(double x) { return std::ceil(x); }
-
-double swift::_swift_stdlib_floor(double x) { return std::floor(x); }
-
-#if (defined __i386__ || defined __x86_64__) && !defined _MSC_VER
-void swift::_swift_stdlib_remainderl(void *_self, const void *_other) {
-  *(long double *)_self = std::remainder(*(long double *)_self,
-                                         *(const long double *)_other);
-}
-
-void swift::_swift_stdlib_squareRootl(void *_self) {
-  *(long double *)_self = std::sqrt(*(long double *)_self);
-}
-
-void
-swift::_swift_stdlib_addProductl(void *_self,
-                                 const void *_lhs, const void *_rhs) {
-  *(long double *)_self = std::fma(*(const long double *)_lhs,
-                                   *(const long double *)_rhs,
-                                   *(long double *)_self);
-}
-
-void swift::_swift_stdlib_roundl(void *_self) {
-  *(long double *)_self = std::round(*(long double *)_self);
-}
-
-void swift::_swift_stdlib_roundevenl(void *_self) {
-  *(long double *)_self = std::rint(*(long double *)_self);
+float swift::_swift_stdlib_sqrtf(float x) {
+  return std::sqrt(x);
 }
 
-void swift::_swift_stdlib_truncl(void *_self) {
-  *(long double *)_self = std::trunc(*(long double *)_self);
+double swift::_swift_stdlib_remainder(double x, double y) {
+  return std::remainder(x, y);
 }
 
-void swift::_swift_stdlib_roundawayl(void *_self) {
-  long double *ptr = (long double *)_self;
-  *ptr =  *ptr < 0 ? std::floor(*ptr) : std::ceil(*ptr);
+double swift::_swift_stdlib_sqrt(double x) {
+  return std::sqrt(x);
 }
 
-void swift::_swift_stdlib_ceill(void *_self) {
-  *(long double *)_self = std::ceil(*(long double *)_self);
+# if (defined __i386__ || defined __x86_64__) && !defined _MSC_VER
+// We use void* for these because the importer doesn't know how to map Float80
+// to long double.
+void swift::_swift_stdlib_remainderl(void *x, const void *y) {
+  long double *ptr = (long double *)x;
+  *ptr = std::remainder(*ptr, *(const long double *)y);
 }
 
-void swift::_swift_stdlib_floorl(void *_self) {
-  *(long double *)_self = std::floor(*(long double *)_self);
+void swift::_swift_stdlib_sqrtl(void *x) {
+  long double *ptr = (long double *)x;
+  *ptr = std::sqrt(*ptr);
 }
-#endif // Have Float80
+# endif
+#endif // !defined __APPLE__