From ff03cea79b710913af1f5decec1952c14ba67812 Mon Sep 17 00:00:00 2001 From: cremno Date: Mon, 5 May 2014 15:22:42 +0200 Subject: temporary macros for checked arithmetic functions --- include/mruby/numeric.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/include/mruby/numeric.h b/include/mruby/numeric.h index 17291c2f2..63a5eb300 100644 --- a/include/mruby/numeric.h +++ b/include/mruby/numeric.h @@ -25,6 +25,21 @@ mrb_value mrb_fixnum_mul(mrb_state *mrb, mrb_value x, mrb_value y); mrb_value mrb_num_div(mrb_state *mrb, mrb_value x, mrb_value y); mrb_float mrb_to_flo(mrb_state *mrb, mrb_value x); +#define MRB_UINT_MAKE2(n) uint ## n ## _t +#define MRB_UINT_MAKE(n) MRB_UINT_MAKE2(n) +#define mrb_uint MRB_UINT_MAKE(MRB_INT_BIT) + +#ifdef MRB_WORD_BOXING +# define MRB_INT_OVERFLOW_MASK ((mrb_uint)1 << (MRB_INT_BIT - 1 - MRB_FIXNUM_SHIFT)) +#else +# define MRB_INT_OVERFLOW_MASK ((mrb_uint)1 << (MRB_INT_BIT - 1)) +#endif + +#undef MRB_INT_OVERFLOW_MASK +#undef mrb_uint +#undef MRB_UINT_MAKE +#undef MRB_UINT_MAKE2 + #if defined(__cplusplus) } /* extern "C" { */ #endif -- cgit v1.2.3 From 0f3930426515848be755c5480df354fa9e2109f4 Mon Sep 17 00:00:00 2001 From: cremno Date: Mon, 5 May 2014 15:24:22 +0200 Subject: add function for checked mrb_int addition --- include/mruby/numeric.h | 10 ++++++++++ src/numeric.c | 4 +--- src/vm.c | 13 ++++--------- 3 files changed, 15 insertions(+), 12 deletions(-) diff --git a/include/mruby/numeric.h b/include/mruby/numeric.h index 63a5eb300..35be32a01 100644 --- a/include/mruby/numeric.h +++ b/include/mruby/numeric.h @@ -35,6 +35,16 @@ mrb_float mrb_to_flo(mrb_state *mrb, mrb_value x); # define MRB_INT_OVERFLOW_MASK ((mrb_uint)1 << (MRB_INT_BIT - 1)) #endif +static inline mrb_bool +mrb_int_add_overflow(mrb_int augend, mrb_int addend, mrb_int *sum) +{ + mrb_uint x = (mrb_uint)augend; + mrb_uint y = (mrb_uint)addend; + mrb_uint z = (mrb_uint)(x + y); + *sum = (mrb_int)z; + return !!(((x ^ z) & (y ^ z)) & MRB_INT_OVERFLOW_MASK); +} + #undef MRB_INT_OVERFLOW_MASK #undef mrb_uint #undef MRB_UINT_MAKE diff --git a/src/numeric.c b/src/numeric.c index 56835edbf..8ea71ada6 100644 --- a/src/numeric.c +++ b/src/numeric.c @@ -1109,9 +1109,7 @@ mrb_fixnum_plus(mrb_state *mrb, mrb_value x, mrb_value y) if (a == 0) return y; b = mrb_fixnum(y); - c = a + b; - if (((a < 0) ^ (b < 0)) == 0 && (a < 0) != (c < 0)) { - /* integer overflow */ + if (mrb_int_add_overflow(a, b, &c)) { return mrb_float_value(mrb, (mrb_float)a + (mrb_float)b); } return mrb_fixnum_value(c); diff --git a/src/vm.c b/src/vm.c index 0e3c0a81e..85a121f2c 100644 --- a/src/vm.c +++ b/src/vm.c @@ -12,6 +12,7 @@ #include "mruby/class.h" #include "mruby/hash.h" #include "mruby/irep.h" +#include "mruby/numeric.h" #include "mruby/proc.h" #include "mruby/range.h" #include "mruby/string.h" @@ -1610,12 +1611,7 @@ RETRY_TRY_BLOCK: x = mrb_fixnum(regs_a[0]); y = mrb_fixnum(regs_a[1]); - z = x + y; -#ifdef MRB_WORD_BOXING - z = (z << MRB_FIXNUM_SHIFT) / (1 << MRB_FIXNUM_SHIFT); -#endif - if ((x < 0) != (z < 0) && ((x < 0) ^ (y < 0)) == 0) { - /* integer overflow */ + if (mrb_int_add_overflow(x, y, &z)) { SET_FLT_VALUE(mrb, regs_a[0], (mrb_float)x + (mrb_float)y); break; } @@ -1842,10 +1838,9 @@ RETRY_TRY_BLOCK: { mrb_int x = regs[a].attr_i; mrb_int y = GETARG_C(i); - mrb_int z = x + y; + mrb_int z; - if (((x < 0) ^ (y < 0)) == 0 && (x < 0) != (z < 0)) { - /* integer overflow */ + if (mrb_int_add_overflow(x, y, &z)) { SET_FLT_VALUE(mrb, regs[a], (mrb_float)x + (mrb_float)y); break; } -- cgit v1.2.3 From cf8df563c0ea9b98714e701ad235acbefc091558 Mon Sep 17 00:00:00 2001 From: cremno Date: Mon, 5 May 2014 15:28:26 +0200 Subject: add function for checked mrb_int subtraction --- include/mruby/numeric.h | 10 ++++++++++ src/numeric.c | 4 +--- src/vm.c | 12 +++--------- 3 files changed, 14 insertions(+), 12 deletions(-) diff --git a/include/mruby/numeric.h b/include/mruby/numeric.h index 35be32a01..fe4f3b264 100644 --- a/include/mruby/numeric.h +++ b/include/mruby/numeric.h @@ -45,6 +45,16 @@ mrb_int_add_overflow(mrb_int augend, mrb_int addend, mrb_int *sum) return !!(((x ^ z) & (y ^ z)) & MRB_INT_OVERFLOW_MASK); } +static inline mrb_bool +mrb_int_sub_overflow(mrb_int minuend, mrb_int subtrahend, mrb_int *difference) +{ + mrb_uint x = (mrb_uint)minuend; + mrb_uint y = (mrb_uint)subtrahend; + mrb_uint z = (mrb_uint)(x - y); + *difference = (mrb_int)z; + return !!(((x ^ z) & (~y ^ z)) & MRB_INT_OVERFLOW_MASK); +} + #undef MRB_INT_OVERFLOW_MASK #undef mrb_uint #undef MRB_UINT_MAKE diff --git a/src/numeric.c b/src/numeric.c index 8ea71ada6..7b025c34d 100644 --- a/src/numeric.c +++ b/src/numeric.c @@ -1145,9 +1145,7 @@ mrb_fixnum_minus(mrb_state *mrb, mrb_value x, mrb_value y) mrb_int b, c; b = mrb_fixnum(y); - c = a - b; - if (((a < 0) ^ (b < 0)) != 0 && (a < 0) != (c < 0)) { - /* integer overflow */ + if (mrb_int_sub_overflow(a, b, &c)) { return mrb_float_value(mrb, (mrb_float)a - (mrb_float)b); } return mrb_fixnum_value(c); diff --git a/src/vm.c b/src/vm.c index 85a121f2c..ae19db0b6 100644 --- a/src/vm.c +++ b/src/vm.c @@ -1669,12 +1669,7 @@ RETRY_TRY_BLOCK: x = mrb_fixnum(regs[a]); y = mrb_fixnum(regs[a+1]); - z = x - y; -#ifdef MRB_WORD_BOXING - z = (z << MRB_FIXNUM_SHIFT) / (1 << MRB_FIXNUM_SHIFT); -#endif - if (((x < 0) ^ (y < 0)) != 0 && (x < 0) != (z < 0)) { - /* integer overflow */ + if (mrb_int_sub_overflow(x, y, &z)) { SET_FLT_VALUE(mrb, regs[a], (mrb_float)x - (mrb_float)y); break; } @@ -1876,10 +1871,9 @@ RETRY_TRY_BLOCK: { mrb_int x = regs_a[0].attr_i; mrb_int y = GETARG_C(i); - mrb_int z = x - y; + mrb_int z; - if ((x < 0) != (z < 0) && ((x < 0) ^ (y < 0)) != 0) { - /* integer overflow */ + if (mrb_int_sub_overflow(x, y, &z)) { SET_FLT_VALUE(mrb, regs_a[0], (mrb_float)x - (mrb_float)y); } else { -- cgit v1.2.3