Fix rounding mode handling: round() and roundf() always round away fr…

…om zero, independent of current active rounding mode, and rint() family should respect the active rounding mode (we only implement one - FE_TONEAREST i.e. round-to-even, or banker's rounding)

src/library.js

@@ -1581,8 +1581,6 @@ LibraryManager.library = {
   llvm_ceil_f64: 'Math_ceil',
   llvm_floor_f32: 'Math_floor',
   llvm_floor_f64: 'Math_floor',
-  llvm_round_f32: 'Math_round',
-  llvm_round_f64: 'Math_round',
 
   llvm_exp2_f32: function(x) {
     return Math.pow(2, x);
@@ -1615,31 +1613,49 @@ LibraryManager.library = {
   },
 
   roundf__asm: true,
-  roundf__sig: 'dd',
-  roundf: function(f) {
+  roundf__sig: 'ff',
+  roundf: function(d) {
+    d = +d;
+    return d >= +0 ? +Math_floor(d + +0.5) : +Math_ceil(d - +0.5);
+  },
+
+  llvm_round_f64__asm: true,
+  llvm_round_f64__sig: 'dd',
+  llvm_round_f64: function(d) {
+    d = +d;
+    return d >= +0 ? +Math_floor(d + +0.5) : +Math_ceil(d - +0.5);
+  },
+
+  llvm_round_f32__asm: true,
+  llvm_round_f32__sig: 'ff',
+  llvm_round_f32: function(f) {
     f = +f;
     return f >= +0 ? +Math_floor(f + +0.5) : +Math_ceil(f - +0.5); // TODO: use fround?
   },
 
+  rintf__asm: true,
+  rintf__sig: 'ff',
+  rintf__deps: ['round'],
+  rintf: function(f) {
+    f = +f;
+    return (f - +Math_floor(f) != .5) ? +_round(f) : +_round(f / +2) * +2;
+  },
+
   // TODO: fround?
   llvm_rint_f32__asm: true,
-  llvm_rint_f32__sig: 'dd',
+  llvm_rint_f32__sig: 'ff',
+  llvm_rint_f32__deps: ['roundf'],
   llvm_rint_f32: function(f) {
     f = +f;
-    if (+Math_abs(+Math_floor(f + +1) - f) < +Math_abs(+Math_ceil(f - +1) - f)) {
-      return +Math_floor(f + +1);
-    }
-    return +Math_ceil(f - +1);
+    return (f - +Math_floor(f) != .5) ? +_roundf(f) : +_roundf(f / +2) * +2;
   },
 
   llvm_rint_f64__asm: true,
   llvm_rint_f64__sig: 'dd',
+  llvm_rint_f64__deps: ['round'],
   llvm_rint_f64: function(f) {
     f = +f;
-    if (+Math_abs(+Math_floor(f + +1) - f) < +Math_abs(+Math_ceil(f - +1) - f)) {
-      return +Math_floor(f + +1);
-    }
-    return +Math_ceil(f - +1);
+    return (f - +Math_floor(f) != .5) ? +_round(f) : +_round(f / +2) * +2;
   },
 
   _reallyNegative: function(x) {

tools/system_libs.py

@@ -112,7 +112,7 @@ def create_libc(libname):
     blacklist = set(
       ['ipc', 'passwd', 'thread', 'signal', 'sched', 'ipc', 'time', 'linux', 'aio', 'exit', 'legacy', 'mq', 'process', 'search', 'setjmp', 'env', 'ldso', 'conf'] + # musl modules
       ['memcpy.c', 'memset.c', 'memmove.c', 'getaddrinfo.c', 'getnameinfo.c', 'inet_addr.c', 'res_query.c', 'gai_strerror.c', 'proto.c', 'gethostbyaddr.c', 'gethostbyaddr_r.c', 'gethostbyname.c', 'gethostbyname2_r.c', 'gethostbyname_r.c', 'gethostbyname2.c', 'usleep.c', 'alarm.c', 'syscall.c', '_exit.c'] + # individual files
-      ['abs.c', 'cos.c', 'cosf.c', 'cosl.c', 'sin.c', 'sinf.c', 'sinl.c', 'tan.c', 'tanf.c', 'tanl.c', 'acos.c', 'acosf.c', 'acosl.c', 'asin.c', 'asinf.c', 'asinl.c', 'atan.c', 'atanf.c', 'atanl.c', 'atan2.c', 'atan2f.c', 'atan2l.c', 'exp.c', 'expf.c', 'expl.c', 'log.c', 'logf.c', 'logl.c', 'sqrt.c', 'sqrtf.c', 'sqrtl.c', 'fabs.c', 'fabsf.c', 'fabsl.c', 'ceil.c', 'ceilf.c', 'ceill.c', 'floor.c', 'floorf.c', 'floorl.c', 'pow.c', 'powf.c', 'powl.c', 'round.c', 'roundf.c'] # individual math files
+      ['abs.c', 'cos.c', 'cosf.c', 'cosl.c', 'sin.c', 'sinf.c', 'sinl.c', 'tan.c', 'tanf.c', 'tanl.c', 'acos.c', 'acosf.c', 'acosl.c', 'asin.c', 'asinf.c', 'asinl.c', 'atan.c', 'atanf.c', 'atanl.c', 'atan2.c', 'atan2f.c', 'atan2l.c', 'exp.c', 'expf.c', 'expl.c', 'log.c', 'logf.c', 'logl.c', 'sqrt.c', 'sqrtf.c', 'sqrtl.c', 'fabs.c', 'fabsf.c', 'fabsl.c', 'ceil.c', 'ceilf.c', 'ceill.c', 'floor.c', 'floorf.c', 'floorl.c', 'pow.c', 'powf.c', 'powl.c', 'round.c', 'roundf.c', 'rintf.c'] # individual math files
     )
     # TODO: consider using more math code from musl, doing so makes box2d faster
     for dirpath, dirnames, filenames in os.walk(musl_srcdir):