* intern.h (rb_divmod): assume compilers `/` and `%` comply C99

  and reduce branching. If a compiler doesn't comply, add #ifdefs.

* intern.h (rb_div): added for Ruby's behavior.

* intern.h (rb_mod): added for Ruby's behavior.

* insns.def (opt_div): use rb_div.

* insns.def (opt_mod): use rb_mod.

* numeric.c (fixdivmod): removed.

* numeric.c (fix_divide): use rb_div.

* numeric.c (fix_mod): use rb_mod.

* numeric.c (fix_divmod): use rb_divmod.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54029 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

4 files changed, 75 insertions, 99 deletions

diff --git a/ChangeLog b/ChangeLog
index 7617567dd2..27cd19daba 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,24 @@
+Tue Mar  8 17:20:21 2016  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* intern.h (rb_divmod): assume compilers `/` and `%` comply C99
+	  and reduce branching. If a compiler doesn't comply, add #ifdefs.
+
+	* intern.h (rb_div): added for Ruby's behavior.
+
+	* intern.h (rb_mod): added for Ruby's behavior.
+
+	* insns.def (opt_div): use rb_div.
+
+	* insns.def (opt_mod): use rb_mod.
+
+	* numeric.c (fixdivmod): removed.
+
+	* numeric.c (fix_divide): use rb_div.
+
+	* numeric.c (fix_mod): use rb_mod.
+
+	* numeric.c (fix_divmod): use rb_divmod.
+
 Tue Mar  8 17:53:09 2016  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* insns.def (opt_mod): show its method name on ZeroDivisionError.
diff --git a/insns.def b/insns.def
index 20140b30c1..98871bf9a6 100644
--- a/insns.def
+++ b/insns.def
@@ -1473,34 +1473,9 @@ opt_div
 {
     if (FIXNUM_2_P(recv, obj) &&
 	BASIC_OP_UNREDEFINED_P(BOP_DIV, FIXNUM_REDEFINED_OP_FLAG)) {
-	long x, y, div;
-
-	x = FIX2LONG(recv);
-	y = FIX2LONG(obj);
-	{
-	    /* copied from numeric.c#fixdivmod */
-	    long mod;
-	    if (y == 0)
-		goto INSN_LABEL(normal_dispatch);
-	    if (y < 0) {
-		if (x < 0)
-		    div = -x / -y;
-		else
-		    div = -(x / -y);
-	    }
-	    else {
-		if (x < 0)
-		    div = -(-x / y);
-		else
-		    div = x / y;
-	    }
-	    mod = x - div * y;
-	    if ((mod < 0 && y > 0) || (mod > 0 && y < 0)) {
-		mod += y;
-		div -= 1;
-	    }
-	}
-	val = LONG2NUM(div);
+	long y = FIX2LONG(obj);
+	if (y == 0) goto INSN_LABEL(normal_dispatch);
+	val = LONG2NUM(rb_div(FIX2LONG(recv), y));
     }
     else if (FLONUM_2_P(recv, obj) &&
 	     BASIC_OP_UNREDEFINED_P(BOP_DIV, FLOAT_REDEFINED_OP_FLAG)) {
@@ -1536,38 +1511,9 @@ opt_mod
 {
     if (FIXNUM_2_P(recv, obj) &&
 	BASIC_OP_UNREDEFINED_P(BOP_MOD, FIXNUM_REDEFINED_OP_FLAG )) {
-	long x, y;
-
-	x = FIX2LONG(recv);
-	y = FIX2LONG(obj);
-	if (x > 0 && y > 0) {
-	    val = LONG2FIX(x % y);
-	}
-	else {
-	    /* copied from numeric.c#fixdivmod */
-	    long div, mod;
-
-	    if (y == 0)
-		goto INSN_LABEL(normal_dispatch);
-	    if (y < 0) {
-		if (x < 0)
-		    div = -x / -y;
-		else
-		    div = -(x / -y);
-	    }
-	    else {
-		if (x < 0)
-		    div = -(-x / y);
-		else
-		    div = x / y;
-	    }
-	    mod = x - div * y;
-	    if ((mod < 0 && y > 0) || (mod > 0 && y < 0)) {
-		mod += y;
-		div -= 1;
-	    }
-	    val = LONG2FIX(mod);
-	}
+	long y = FIX2LONG(obj);
+	if (y == 0) goto INSN_LABEL(normal_dispatch);
+	val = LONG2FIX(rb_mod(FIX2LONG(recv), y));
     }
     else if (FLONUM_2_P(recv, obj) &&
 	     BASIC_OP_UNREDEFINED_P(BOP_MOD, FLOAT_REDEFINED_OP_FLAG)) {
diff --git a/internal.h b/internal.h
index edf7f4f6c4..76746cc3b7 100644
--- a/internal.h
+++ b/internal.h
@@ -266,6 +266,47 @@ nlz_int128(uint128_t x)
 }
 #endif
 
+/*
+ * This behaves different from C99 for negative arguments.
+ * Note that div may overflow fixnum.
+ */
+static inline void
+rb_divmod(long x, long y, long *divp, long *modp) {
+    /* assume / and % comply C99.
+     * ldiv(3) won't be inlined by GCC and clang.
+     * I expect / and % are compiled as single idiv.
+     */
+    long div = x / y;
+    long mod = x % y;
+    if (y > 0 ? mod < 0 : mod > 0) {
+	mod += y;
+	div -= 1;
+    }
+    if (divp) *divp = div;
+    if (modp) *modp = mod;
+}
+
+/* div() for Ruby
+ * This behaves different from C99 for negative arguments.
+ * Note that div may overflow fixnum
+ */
+static inline long
+rb_div(long x, long y) {
+    long div;
+    rb_divmod(x, y, &div, NULL);
+    return div;
+}
+
+/* mod() for Ruby
+ * This behaves different from C99 for negative arguments.
+ */
+static inline long
+rb_mod(long x, long y) {
+    long mod;
+    rb_divmod(x, y, NULL, &mod);
+    return mod;
+}
+
 #if defined(HAVE_UINT128_T)
 #   define bit_length(x) \
     (sizeof(x) <= SIZEOF_INT ? SIZEOF_INT * CHAR_BIT - nlz_int((unsigned int)(x)) : \
diff --git a/numeric.c b/numeric.c
index c424203109..1e5f779ae9 100644
--- a/numeric.c
+++ b/numeric.c
@@ -3079,33 +3079,6 @@ fix_mul(VALUE x, VALUE y)
     }
 }
 
-static void
-fixdivmod(long x, long y, long *divp, long *modp)
-{
-    long div, mod;
-
-    if (y == 0) rb_num_zerodiv();
-    if (y < 0) {
-	if (x < 0)
-	    div = -x / -y;
-	else
-	    div = - (x / -y);
-    }
-    else {
-	if (x < 0)
-	    div = - (-x / y);
-	else
-	    div = x / y;
-    }
-    mod = x - div*y;
-    if ((mod < 0 && y > 0) || (mod > 0 && y < 0)) {
-	mod += y;
-	div -= 1;
-    }
-    if (divp) *divp = div;
-    if (modp) *modp = mod;
-}
-
 /*
  *  call-seq:
  *     fix.fdiv(numeric)  ->  float
@@ -3138,10 +3111,8 @@ static VALUE
 fix_divide(VALUE x, VALUE y, ID op)
 {
     if (FIXNUM_P(y)) {
-	long div;
-
-	fixdivmod(FIX2LONG(x), FIX2LONG(y), &div, 0);
-	return LONG2NUM(div);
+	if (FIX2LONG(y) == 0) rb_num_zerodiv();
+	return LONG2NUM(rb_div(FIX2LONG(x), FIX2LONG(y)));
     }
     else if (RB_TYPE_P(y, T_BIGNUM)) {
 	x = rb_int2big(FIX2LONG(x));
@@ -3212,10 +3183,8 @@ static VALUE
 fix_mod(VALUE x, VALUE y)
 {
     if (FIXNUM_P(y)) {
-	long mod;
-
-	fixdivmod(FIX2LONG(x), FIX2LONG(y), 0, &mod);
-	return LONG2NUM(mod);
+	if (FIX2LONG(y) == 0) rb_num_zerodiv();
+	return LONG2FIX(rb_mod(FIX2LONG(x), FIX2LONG(y)));
     }
     else if (RB_TYPE_P(y, T_BIGNUM)) {
 	x = rb_int2big(FIX2LONG(x));
@@ -3240,10 +3209,9 @@ fix_divmod(VALUE x, VALUE y)
 {
     if (FIXNUM_P(y)) {
 	long div, mod;
-
-	fixdivmod(FIX2LONG(x), FIX2LONG(y), &div, &mod);
-
-	return rb_assoc_new(LONG2NUM(div), LONG2NUM(mod));
+	if (FIX2LONG(y) == 0) rb_num_zerodiv();
+	rb_divmod(FIX2LONG(x), FIX2LONG(y), &div, &mod);
+	return rb_assoc_new(LONG2NUM(div), LONG2FIX(mod));
     }
     else if (RB_TYPE_P(y, T_BIGNUM)) {
 	x = rb_int2big(FIX2LONG(x));