Moved the builtins documentation to lib/builtins/

And fixed typos in the ASan readme.

Differential Revision: http://reviews.llvm.org/D3927

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@209778 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 346 insertions, 336 deletions

diff --git a/README.txt b/README.txt
index 1c08e7415..fc8843246 100644
--- a/README.txt
+++ b/README.txt
@@ -9,335 +9,3 @@ terms of the license agreement found in LICENSE.txt.
 
 ================================
 
-This is a replacement library for libgcc.  Each function is contained
-in its own file.  Each function has a corresponding unit test under
-test/Unit.
-
-A rudimentary script to test each file is in the file called
-test/Unit/test.
-
-Here is the specification for this library:
-
-http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc
-
-Here is a synopsis of the contents of this library:
-
-typedef      int si_int;
-typedef unsigned su_int;
-
-typedef          long long di_int;
-typedef unsigned long long du_int;
-
-// Integral bit manipulation
-
-di_int __ashldi3(di_int a, si_int b);      // a << b
-ti_int __ashlti3(ti_int a, si_int b);      // a << b
-
-di_int __ashrdi3(di_int a, si_int b);      // a >> b  arithmetic (sign fill)
-ti_int __ashrti3(ti_int a, si_int b);      // a >> b  arithmetic (sign fill)
-di_int __lshrdi3(di_int a, si_int b);      // a >> b  logical    (zero fill)
-ti_int __lshrti3(ti_int a, si_int b);      // a >> b  logical    (zero fill)
-
-si_int __clzsi2(si_int a);  // count leading zeros
-si_int __clzdi2(di_int a);  // count leading zeros
-si_int __clzti2(ti_int a);  // count leading zeros
-si_int __ctzsi2(si_int a);  // count trailing zeros
-si_int __ctzdi2(di_int a);  // count trailing zeros
-si_int __ctzti2(ti_int a);  // count trailing zeros
-
-si_int __ffsdi2(di_int a);  // find least significant 1 bit
-si_int __ffsti2(ti_int a);  // find least significant 1 bit
-
-si_int __paritysi2(si_int a);  // bit parity
-si_int __paritydi2(di_int a);  // bit parity
-si_int __parityti2(ti_int a);  // bit parity
-
-si_int __popcountsi2(si_int a);  // bit population
-si_int __popcountdi2(di_int a);  // bit population
-si_int __popcountti2(ti_int a);  // bit population
-
-uint32_t __bswapsi2(uint32_t a);   // a byteswapped, arm only
-uint64_t __bswapdi2(uint64_t a);   // a byteswapped, arm only
-
-// Integral arithmetic
-
-di_int __negdi2    (di_int a);                         // -a
-ti_int __negti2    (ti_int a);                         // -a
-di_int __muldi3    (di_int a, di_int b);               // a * b
-ti_int __multi3    (ti_int a, ti_int b);               // a * b
-si_int __divsi3    (si_int a, si_int b);               // a / b   signed
-di_int __divdi3    (di_int a, di_int b);               // a / b   signed
-ti_int __divti3    (ti_int a, ti_int b);               // a / b   signed
-su_int __udivsi3   (su_int n, su_int d);               // a / b   unsigned
-du_int __udivdi3   (du_int a, du_int b);               // a / b   unsigned
-tu_int __udivti3   (tu_int a, tu_int b);               // a / b   unsigned
-si_int __modsi3    (si_int a, si_int b);               // a % b   signed
-di_int __moddi3    (di_int a, di_int b);               // a % b   signed
-ti_int __modti3    (ti_int a, ti_int b);               // a % b   signed
-su_int __umodsi3   (su_int a, su_int b);               // a % b   unsigned
-du_int __umoddi3   (du_int a, du_int b);               // a % b   unsigned
-tu_int __umodti3   (tu_int a, tu_int b);               // a % b   unsigned
-du_int __udivmoddi4(du_int a, du_int b, du_int* rem);  // a / b, *rem = a % b  unsigned
-tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem);  // a / b, *rem = a % b  unsigned
-su_int __udivmodsi4(su_int a, su_int b, su_int* rem);  // a / b, *rem = a % b  unsigned
-si_int __divmodsi4(si_int a, si_int b, si_int* rem);   // a / b, *rem = a % b  signed
-
-
-
-//  Integral arithmetic with trapping overflow
-
-si_int __absvsi2(si_int a);           // abs(a)
-di_int __absvdi2(di_int a);           // abs(a)
-ti_int __absvti2(ti_int a);           // abs(a)
-
-si_int __negvsi2(si_int a);           // -a
-di_int __negvdi2(di_int a);           // -a
-ti_int __negvti2(ti_int a);           // -a
-
-si_int __addvsi3(si_int a, si_int b);  // a + b
-di_int __addvdi3(di_int a, di_int b);  // a + b
-ti_int __addvti3(ti_int a, ti_int b);  // a + b
-
-si_int __subvsi3(si_int a, si_int b);  // a - b
-di_int __subvdi3(di_int a, di_int b);  // a - b
-ti_int __subvti3(ti_int a, ti_int b);  // a - b
-
-si_int __mulvsi3(si_int a, si_int b);  // a * b
-di_int __mulvdi3(di_int a, di_int b);  // a * b
-ti_int __mulvti3(ti_int a, ti_int b);  // a * b
-
-
-// Integral arithmetic which returns if overflow
-
-si_int __mulosi4(si_int a, si_int b, int* overflow);  // a * b, overflow set to one if result not in signed range
-di_int __mulodi4(di_int a, di_int b, int* overflow);  // a * b, overflow set to one if result not in signed range
-ti_int __muloti4(ti_int a, ti_int b, int* overflow);  // a * b, overflow set to
- one if result not in signed range
-
-
-//  Integral comparison: a  < b -> 0
-//                       a == b -> 1
-//                       a  > b -> 2
-
-si_int __cmpdi2 (di_int a, di_int b);
-si_int __cmpti2 (ti_int a, ti_int b);
-si_int __ucmpdi2(du_int a, du_int b);
-si_int __ucmpti2(tu_int a, tu_int b);
-
-//  Integral / floating point conversion
-
-di_int __fixsfdi(      float a);
-di_int __fixdfdi(     double a);
-di_int __fixxfdi(long double a);
-
-ti_int __fixsfti(      float a);
-ti_int __fixdfti(     double a);
-ti_int __fixxfti(long double a);
-uint64_t __fixtfdi(long double input);  // ppc only, doesn't match documentation
-
-su_int __fixunssfsi(      float a);
-su_int __fixunsdfsi(     double a);
-su_int __fixunsxfsi(long double a);
-
-du_int __fixunssfdi(      float a);
-du_int __fixunsdfdi(     double a);
-du_int __fixunsxfdi(long double a);
-
-tu_int __fixunssfti(      float a);
-tu_int __fixunsdfti(     double a);
-tu_int __fixunsxfti(long double a);
-uint64_t __fixunstfdi(long double input);  // ppc only
-
-float       __floatdisf(di_int a);
-double      __floatdidf(di_int a);
-long double __floatdixf(di_int a);
-long double __floatditf(int64_t a);        // ppc only
-
-float       __floattisf(ti_int a);
-double      __floattidf(ti_int a);
-long double __floattixf(ti_int a);
-
-float       __floatundisf(du_int a);
-double      __floatundidf(du_int a);
-long double __floatundixf(du_int a);
-long double __floatunditf(uint64_t a);     // ppc only
-
-float       __floatuntisf(tu_int a);
-double      __floatuntidf(tu_int a);
-long double __floatuntixf(tu_int a);
-
-//  Floating point raised to integer power
-
-float       __powisf2(      float a, si_int b);  // a ^ b
-double      __powidf2(     double a, si_int b);  // a ^ b
-long double __powixf2(long double a, si_int b);  // a ^ b
-long double __powitf2(long double a, si_int b);  // ppc only, a ^ b
-
-//  Complex arithmetic
-
-//  (a + ib) * (c + id)
-
-      float _Complex __mulsc3( float a,  float b,  float c,  float d);
-     double _Complex __muldc3(double a, double b, double c, double d);
-long double _Complex __mulxc3(long double a, long double b,
-                              long double c, long double d);
-long double _Complex __multc3(long double a, long double b,
-                              long double c, long double d); // ppc only
-
-//  (a + ib) / (c + id)
-
-      float _Complex __divsc3( float a,  float b,  float c,  float d);
-     double _Complex __divdc3(double a, double b, double c, double d);
-long double _Complex __divxc3(long double a, long double b,
-                              long double c, long double d);
-long double _Complex __divtc3(long double a, long double b,
-                              long double c, long double d);  // ppc only
-
-
-//         Runtime support
-
-// __clear_cache() is used to tell process that new instructions have been
-// written to an address range.  Necessary on processors that do not have
-// a unified instruction and data cache.
-void __clear_cache(void* start, void* end);
-
-// __enable_execute_stack() is used with nested functions when a trampoline
-// function is written onto the stack and that page range needs to be made
-// executable.
-void __enable_execute_stack(void* addr);
-
-// __gcc_personality_v0() is normally only called by the system unwinder.
-// C code (as opposed to C++) normally does not need a personality function
-// because there are no catch clauses or destructors to be run.  But there
-// is a C language extension __attribute__((cleanup(func))) which marks local
-// variables as needing the cleanup function "func" to be run when the
-// variable goes out of scope.  That includes when an exception is thrown,
-// so a personality handler is needed.  
-_Unwind_Reason_Code __gcc_personality_v0(int version, _Unwind_Action actions,
-         uint64_t exceptionClass, struct _Unwind_Exception* exceptionObject,
-         _Unwind_Context_t context);
-
-// for use with some implementations of assert() in <assert.h>
-void __eprintf(const char* format, const char* assertion_expression,
-				const char* line, const char* file);
-				
-
-
-//   Power PC specific functions
-
-// There is no C interface to the saveFP/restFP functions.  They are helper
-// functions called by the prolog and epilog of functions that need to save
-// a number of non-volatile float point registers.  
-saveFP
-restFP
-
-// PowerPC has a standard template for trampoline functions.  This function
-// generates a custom trampoline function with the specific realFunc
-// and localsPtr values.
-void __trampoline_setup(uint32_t* trampOnStack, int trampSizeAllocated, 
-                                const void* realFunc, void* localsPtr);
-
-// adds two 128-bit double-double precision values ( x + y )
-long double __gcc_qadd(long double x, long double y);  
-
-// subtracts two 128-bit double-double precision values ( x - y )
-long double __gcc_qsub(long double x, long double y); 
-
-// multiples two 128-bit double-double precision values ( x * y )
-long double __gcc_qmul(long double x, long double y);  
-
-// divides two 128-bit double-double precision values ( x / y )
-long double __gcc_qdiv(long double a, long double b);  
-
-
-//    ARM specific functions
-
-// There is no C interface to the switch* functions.  These helper functions
-// are only needed by Thumb1 code for efficient switch table generation.
-switch16
-switch32
-switch8
-switchu8
-
-// There is no C interface to the *_vfp_d8_d15_regs functions.  There are
-// called in the prolog and epilog of Thumb1 functions.  When the C++ ABI use
-// SJLJ for exceptions, each function with a catch clause or destuctors needs
-// to save and restore all registers in it prolog and epliog.  But there is 
-// no way to access vector and high float registers from thumb1 code, so the 
-// compiler must add call outs to these helper functions in the prolog and 
-// epilog.
-restore_vfp_d8_d15_regs
-save_vfp_d8_d15_regs
-
-
-// Note: long ago ARM processors did not have floating point hardware support.
-// Floating point was done in software and floating point parameters were 
-// passed in integer registers.  When hardware support was added for floating
-// point, new *vfp functions were added to do the same operations but with 
-// floating point parameters in floating point registers.
-
-// Undocumented functions
-
-float  __addsf3vfp(float a, float b);   // Appears to return a + b
-double __adddf3vfp(double a, double b); // Appears to return a + b
-float  __divsf3vfp(float a, float b);   // Appears to return a / b
-double __divdf3vfp(double a, double b); // Appears to return a / b
-int    __eqsf2vfp(float a, float b);    // Appears to return  one
-                                        //     iff a == b and neither is NaN.
-int    __eqdf2vfp(double a, double b);  // Appears to return  one
-                                        //     iff a == b and neither is NaN.
-double __extendsfdf2vfp(float a);       // Appears to convert from
-                                        //     float to double.
-int    __fixdfsivfp(double a);          // Appears to convert from
-                                        //     double to int.
-int    __fixsfsivfp(float a);           // Appears to convert from
-                                        //     float to int.
-unsigned int __fixunssfsivfp(float a);  // Appears to convert from
-                                        //     float to unsigned int.
-unsigned int __fixunsdfsivfp(double a); // Appears to convert from
-                                        //     double to unsigned int.
-double __floatsidfvfp(int a);           // Appears to convert from
-                                        //     int to double.
-float __floatsisfvfp(int a);            // Appears to convert from
-                                        //     int to float.
-double __floatunssidfvfp(unsigned int a); // Appears to convert from
-                                        //     unisgned int to double.
-float __floatunssisfvfp(unsigned int a); // Appears to convert from
-                                        //     unisgned int to float.
-int __gedf2vfp(double a, double b);     // Appears to return __gedf2
-                                        //     (a >= b)
-int __gesf2vfp(float a, float b);       // Appears to return __gesf2
-                                        //     (a >= b)
-int __gtdf2vfp(double a, double b);     // Appears to return __gtdf2
-                                        //     (a > b)
-int __gtsf2vfp(float a, float b);       // Appears to return __gtsf2
-                                        //     (a > b)
-int __ledf2vfp(double a, double b);     // Appears to return __ledf2
-                                        //     (a <= b)
-int __lesf2vfp(float a, float b);       // Appears to return __lesf2
-                                        //     (a <= b)
-int __ltdf2vfp(double a, double b);     // Appears to return __ltdf2
-                                        //     (a < b)
-int __ltsf2vfp(float a, float b);       // Appears to return __ltsf2
-                                        //     (a < b)
-double __muldf3vfp(double a, double b); // Appears to return a * b
-float __mulsf3vfp(float a, float b);    // Appears to return a * b
-int __nedf2vfp(double a, double b);     // Appears to return __nedf2
-                                        //     (a != b)
-double __negdf2vfp(double a);           // Appears to return -a
-float __negsf2vfp(float a);             // Appears to return -a
-float __negsf2vfp(float a);             // Appears to return -a
-double __subdf3vfp(double a, double b); // Appears to return a - b
-float __subsf3vfp(float a, float b);    // Appears to return a - b
-float __truncdfsf2vfp(double a);        // Appears to convert from
-                                        //     double to float.
-int __unorddf2vfp(double a, double b);  // Appears to return __unorddf2
-int __unordsf2vfp(float a, float b);    // Appears to return __unordsf2
-
-
-Preconditions are listed for each function at the definition when there are any.
-Any preconditions reflect the specification at
-http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc.
-
-Assumptions are listed in "int_lib.h", and in individual files.  Where possible
-assumptions are checked at compile time.
diff --git a/lib/asan/README.txt b/lib/asan/README.txt
index e4f4961c5..b9c43acd5 100644
--- a/lib/asan/README.txt
+++ b/lib/asan/README.txt
@@ -1,16 +1,15 @@
 AddressSanitizer RT
 ================================
-This directory contains sources of the AddressSanitizer (asan) run-time library.
+This directory contains sources of the AddressSanitizer (asan) runtime library.
 We are in the process of integrating AddressSanitizer with LLVM, stay tuned.
 
-Directory structre:
+Directory structure:
 README.txt       : This file.
 Makefile.mk      : File for make-based build.
 CMakeLists.txt   : File for cmake-based build.
-asan_*.{cc,h}    : Sources of the asan run-time lirbary.
+asan_*.{cc,h}    : Sources of the asan runtime library.
 scripts/*        : Helper scripts.
 tests/*          : ASan unit tests.
-lit_tests/*      : ASan output tests.
 
 Also ASan runtime needs the following libraries:
 lib/interception/      : Machinery used to intercept function calls.
diff --git a/lib/builtins/README.txt b/lib/builtins/README.txt
new file mode 100644
index 000000000..1c08e7415
--- /dev/null
+++ b/lib/builtins/README.txt
@@ -0,0 +1,343 @@
+Compiler-RT
+================================
+
+This directory and its subdirectories contain source code for the compiler
+support routines.
+
+Compiler-RT is open source software. You may freely distribute it under the
+terms of the license agreement found in LICENSE.txt.
+
+================================
+
+This is a replacement library for libgcc.  Each function is contained
+in its own file.  Each function has a corresponding unit test under
+test/Unit.
+
+A rudimentary script to test each file is in the file called
+test/Unit/test.
+
+Here is the specification for this library:
+
+http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc
+
+Here is a synopsis of the contents of this library:
+
+typedef      int si_int;
+typedef unsigned su_int;
+
+typedef          long long di_int;
+typedef unsigned long long du_int;
+
+// Integral bit manipulation
+
+di_int __ashldi3(di_int a, si_int b);      // a << b
+ti_int __ashlti3(ti_int a, si_int b);      // a << b
+
+di_int __ashrdi3(di_int a, si_int b);      // a >> b  arithmetic (sign fill)
+ti_int __ashrti3(ti_int a, si_int b);      // a >> b  arithmetic (sign fill)
+di_int __lshrdi3(di_int a, si_int b);      // a >> b  logical    (zero fill)
+ti_int __lshrti3(ti_int a, si_int b);      // a >> b  logical    (zero fill)
+
+si_int __clzsi2(si_int a);  // count leading zeros
+si_int __clzdi2(di_int a);  // count leading zeros
+si_int __clzti2(ti_int a);  // count leading zeros
+si_int __ctzsi2(si_int a);  // count trailing zeros
+si_int __ctzdi2(di_int a);  // count trailing zeros
+si_int __ctzti2(ti_int a);  // count trailing zeros
+
+si_int __ffsdi2(di_int a);  // find least significant 1 bit
+si_int __ffsti2(ti_int a);  // find least significant 1 bit
+
+si_int __paritysi2(si_int a);  // bit parity
+si_int __paritydi2(di_int a);  // bit parity
+si_int __parityti2(ti_int a);  // bit parity
+
+si_int __popcountsi2(si_int a);  // bit population
+si_int __popcountdi2(di_int a);  // bit population
+si_int __popcountti2(ti_int a);  // bit population
+
+uint32_t __bswapsi2(uint32_t a);   // a byteswapped, arm only
+uint64_t __bswapdi2(uint64_t a);   // a byteswapped, arm only
+
+// Integral arithmetic
+
+di_int __negdi2    (di_int a);                         // -a
+ti_int __negti2    (ti_int a);                         // -a
+di_int __muldi3    (di_int a, di_int b);               // a * b
+ti_int __multi3    (ti_int a, ti_int b);               // a * b
+si_int __divsi3    (si_int a, si_int b);               // a / b   signed
+di_int __divdi3    (di_int a, di_int b);               // a / b   signed
+ti_int __divti3    (ti_int a, ti_int b);               // a / b   signed
+su_int __udivsi3   (su_int n, su_int d);               // a / b   unsigned
+du_int __udivdi3   (du_int a, du_int b);               // a / b   unsigned
+tu_int __udivti3   (tu_int a, tu_int b);               // a / b   unsigned
+si_int __modsi3    (si_int a, si_int b);               // a % b   signed
+di_int __moddi3    (di_int a, di_int b);               // a % b   signed
+ti_int __modti3    (ti_int a, ti_int b);               // a % b   signed
+su_int __umodsi3   (su_int a, su_int b);               // a % b   unsigned
+du_int __umoddi3   (du_int a, du_int b);               // a % b   unsigned
+tu_int __umodti3   (tu_int a, tu_int b);               // a % b   unsigned
+du_int __udivmoddi4(du_int a, du_int b, du_int* rem);  // a / b, *rem = a % b  unsigned
+tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem);  // a / b, *rem = a % b  unsigned
+su_int __udivmodsi4(su_int a, su_int b, su_int* rem);  // a / b, *rem = a % b  unsigned
+si_int __divmodsi4(si_int a, si_int b, si_int* rem);   // a / b, *rem = a % b  signed
+
+
+
+//  Integral arithmetic with trapping overflow
+
+si_int __absvsi2(si_int a);           // abs(a)
+di_int __absvdi2(di_int a);           // abs(a)
+ti_int __absvti2(ti_int a);           // abs(a)
+
+si_int __negvsi2(si_int a);           // -a
+di_int __negvdi2(di_int a);           // -a
+ti_int __negvti2(ti_int a);           // -a
+
+si_int __addvsi3(si_int a, si_int b);  // a + b
+di_int __addvdi3(di_int a, di_int b);  // a + b
+ti_int __addvti3(ti_int a, ti_int b);  // a + b
+
+si_int __subvsi3(si_int a, si_int b);  // a - b
+di_int __subvdi3(di_int a, di_int b);  // a - b
+ti_int __subvti3(ti_int a, ti_int b);  // a - b
+
+si_int __mulvsi3(si_int a, si_int b);  // a * b
+di_int __mulvdi3(di_int a, di_int b);  // a * b
+ti_int __mulvti3(ti_int a, ti_int b);  // a * b
+
+
+// Integral arithmetic which returns if overflow
+
+si_int __mulosi4(si_int a, si_int b, int* overflow);  // a * b, overflow set to one if result not in signed range
+di_int __mulodi4(di_int a, di_int b, int* overflow);  // a * b, overflow set to one if result not in signed range
+ti_int __muloti4(ti_int a, ti_int b, int* overflow);  // a * b, overflow set to
+ one if result not in signed range
+
+
+//  Integral comparison: a  < b -> 0
+//                       a == b -> 1
+//                       a  > b -> 2
+
+si_int __cmpdi2 (di_int a, di_int b);
+si_int __cmpti2 (ti_int a, ti_int b);
+si_int __ucmpdi2(du_int a, du_int b);
+si_int __ucmpti2(tu_int a, tu_int b);
+
+//  Integral / floating point conversion
+
+di_int __fixsfdi(      float a);
+di_int __fixdfdi(     double a);
+di_int __fixxfdi(long double a);
+
+ti_int __fixsfti(      float a);
+ti_int __fixdfti(     double a);
+ti_int __fixxfti(long double a);
+uint64_t __fixtfdi(long double input);  // ppc only, doesn't match documentation
+
+su_int __fixunssfsi(      float a);
+su_int __fixunsdfsi(     double a);
+su_int __fixunsxfsi(long double a);
+
+du_int __fixunssfdi(      float a);
+du_int __fixunsdfdi(     double a);
+du_int __fixunsxfdi(long double a);
+
+tu_int __fixunssfti(      float a);
+tu_int __fixunsdfti(     double a);
+tu_int __fixunsxfti(long double a);
+uint64_t __fixunstfdi(long double input);  // ppc only
+
+float       __floatdisf(di_int a);
+double      __floatdidf(di_int a);
+long double __floatdixf(di_int a);
+long double __floatditf(int64_t a);        // ppc only
+
+float       __floattisf(ti_int a);
+double      __floattidf(ti_int a);
+long double __floattixf(ti_int a);
+
+float       __floatundisf(du_int a);
+double      __floatundidf(du_int a);
+long double __floatundixf(du_int a);
+long double __floatunditf(uint64_t a);     // ppc only
+
+float       __floatuntisf(tu_int a);
+double      __floatuntidf(tu_int a);
+long double __floatuntixf(tu_int a);
+
+//  Floating point raised to integer power
+
+float       __powisf2(      float a, si_int b);  // a ^ b
+double      __powidf2(     double a, si_int b);  // a ^ b
+long double __powixf2(long double a, si_int b);  // a ^ b
+long double __powitf2(long double a, si_int b);  // ppc only, a ^ b
+
+//  Complex arithmetic
+
+//  (a + ib) * (c + id)
+
+      float _Complex __mulsc3( float a,  float b,  float c,  float d);
+     double _Complex __muldc3(double a, double b, double c, double d);
+long double _Complex __mulxc3(long double a, long double b,
+                              long double c, long double d);
+long double _Complex __multc3(long double a, long double b,
+                              long double c, long double d); // ppc only
+
+//  (a + ib) / (c + id)
+
+      float _Complex __divsc3( float a,  float b,  float c,  float d);
+     double _Complex __divdc3(double a, double b, double c, double d);
+long double _Complex __divxc3(long double a, long double b,
+                              long double c, long double d);
+long double _Complex __divtc3(long double a, long double b,
+                              long double c, long double d);  // ppc only
+
+
+//         Runtime support
+
+// __clear_cache() is used to tell process that new instructions have been
+// written to an address range.  Necessary on processors that do not have
+// a unified instruction and data cache.
+void __clear_cache(void* start, void* end);
+
+// __enable_execute_stack() is used with nested functions when a trampoline
+// function is written onto the stack and that page range needs to be made
+// executable.
+void __enable_execute_stack(void* addr);
+
+// __gcc_personality_v0() is normally only called by the system unwinder.
+// C code (as opposed to C++) normally does not need a personality function
+// because there are no catch clauses or destructors to be run.  But there
+// is a C language extension __attribute__((cleanup(func))) which marks local
+// variables as needing the cleanup function "func" to be run when the
+// variable goes out of scope.  That includes when an exception is thrown,
+// so a personality handler is needed.  
+_Unwind_Reason_Code __gcc_personality_v0(int version, _Unwind_Action actions,
+         uint64_t exceptionClass, struct _Unwind_Exception* exceptionObject,
+         _Unwind_Context_t context);
+
+// for use with some implementations of assert() in <assert.h>
+void __eprintf(const char* format, const char* assertion_expression,
+				const char* line, const char* file);
+				
+
+
+//   Power PC specific functions
+
+// There is no C interface to the saveFP/restFP functions.  They are helper
+// functions called by the prolog and epilog of functions that need to save
+// a number of non-volatile float point registers.  
+saveFP
+restFP
+
+// PowerPC has a standard template for trampoline functions.  This function
+// generates a custom trampoline function with the specific realFunc
+// and localsPtr values.
+void __trampoline_setup(uint32_t* trampOnStack, int trampSizeAllocated, 
+                                const void* realFunc, void* localsPtr);
+
+// adds two 128-bit double-double precision values ( x + y )
+long double __gcc_qadd(long double x, long double y);  
+
+// subtracts two 128-bit double-double precision values ( x - y )
+long double __gcc_qsub(long double x, long double y); 
+
+// multiples two 128-bit double-double precision values ( x * y )
+long double __gcc_qmul(long double x, long double y);  
+
+// divides two 128-bit double-double precision values ( x / y )
+long double __gcc_qdiv(long double a, long double b);  
+
+
+//    ARM specific functions
+
+// There is no C interface to the switch* functions.  These helper functions
+// are only needed by Thumb1 code for efficient switch table generation.
+switch16
+switch32
+switch8
+switchu8
+
+// There is no C interface to the *_vfp_d8_d15_regs functions.  There are
+// called in the prolog and epilog of Thumb1 functions.  When the C++ ABI use
+// SJLJ for exceptions, each function with a catch clause or destuctors needs
+// to save and restore all registers in it prolog and epliog.  But there is 
+// no way to access vector and high float registers from thumb1 code, so the 
+// compiler must add call outs to these helper functions in the prolog and 
+// epilog.
+restore_vfp_d8_d15_regs
+save_vfp_d8_d15_regs
+
+
+// Note: long ago ARM processors did not have floating point hardware support.
+// Floating point was done in software and floating point parameters were 
+// passed in integer registers.  When hardware support was added for floating
+// point, new *vfp functions were added to do the same operations but with 
+// floating point parameters in floating point registers.
+
+// Undocumented functions
+
+float  __addsf3vfp(float a, float b);   // Appears to return a + b
+double __adddf3vfp(double a, double b); // Appears to return a + b
+float  __divsf3vfp(float a, float b);   // Appears to return a / b
+double __divdf3vfp(double a, double b); // Appears to return a / b
+int    __eqsf2vfp(float a, float b);    // Appears to return  one
+                                        //     iff a == b and neither is NaN.
+int    __eqdf2vfp(double a, double b);  // Appears to return  one
+                                        //     iff a == b and neither is NaN.
+double __extendsfdf2vfp(float a);       // Appears to convert from
+                                        //     float to double.
+int    __fixdfsivfp(double a);          // Appears to convert from
+                                        //     double to int.
+int    __fixsfsivfp(float a);           // Appears to convert from
+                                        //     float to int.
+unsigned int __fixunssfsivfp(float a);  // Appears to convert from
+                                        //     float to unsigned int.
+unsigned int __fixunsdfsivfp(double a); // Appears to convert from
+                                        //     double to unsigned int.
+double __floatsidfvfp(int a);           // Appears to convert from
+                                        //     int to double.
+float __floatsisfvfp(int a);            // Appears to convert from
+                                        //     int to float.
+double __floatunssidfvfp(unsigned int a); // Appears to convert from
+                                        //     unisgned int to double.
+float __floatunssisfvfp(unsigned int a); // Appears to convert from
+                                        //     unisgned int to float.
+int __gedf2vfp(double a, double b);     // Appears to return __gedf2
+                                        //     (a >= b)
+int __gesf2vfp(float a, float b);       // Appears to return __gesf2
+                                        //     (a >= b)
+int __gtdf2vfp(double a, double b);     // Appears to return __gtdf2
+                                        //     (a > b)
+int __gtsf2vfp(float a, float b);       // Appears to return __gtsf2
+                                        //     (a > b)
+int __ledf2vfp(double a, double b);     // Appears to return __ledf2
+                                        //     (a <= b)
+int __lesf2vfp(float a, float b);       // Appears to return __lesf2
+                                        //     (a <= b)
+int __ltdf2vfp(double a, double b);     // Appears to return __ltdf2
+                                        //     (a < b)
+int __ltsf2vfp(float a, float b);       // Appears to return __ltsf2
+                                        //     (a < b)
+double __muldf3vfp(double a, double b); // Appears to return a * b
+float __mulsf3vfp(float a, float b);    // Appears to return a * b
+int __nedf2vfp(double a, double b);     // Appears to return __nedf2
+                                        //     (a != b)
+double __negdf2vfp(double a);           // Appears to return -a
+float __negsf2vfp(float a);             // Appears to return -a
+float __negsf2vfp(float a);             // Appears to return -a
+double __subdf3vfp(double a, double b); // Appears to return a - b
+float __subsf3vfp(float a, float b);    // Appears to return a - b
+float __truncdfsf2vfp(double a);        // Appears to convert from
+                                        //     double to float.
+int __unorddf2vfp(double a, double b);  // Appears to return __unorddf2
+int __unordsf2vfp(float a, float b);    // Appears to return __unordsf2
+
+
+Preconditions are listed for each function at the definition when there are any.
+Any preconditions reflect the specification at
+http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc.
+
+Assumptions are listed in "int_lib.h", and in individual files.  Where possible
+assumptions are checked at compile time.