klisp

commit 70e87112d3aa47380efff102729ce317139072c7
parent bf4f1011deb30136bfb694ee55cca0b984f02f8f
Author: Andres Navarro <canavarro82@gmail.com>
Date:   Wed,  6 Apr 2011 11:42:14 -0300

Bugfix: klcm32_64 was dividing by gcd twice instead of once.

Diffstat:
M
src/kghelpers.c
 | 
8
++++----
M
src/kghelpers.h
 | 
1
+

2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/src/kghelpers.c b/src/kghelpers.c
@@ -295,8 +295,8 @@ int64_t kgcd32_64(int32_t a_, int32_t b_)
 int64_t klcm32_64(int32_t a_, int32_t b_)
 {
     int64_t gcd = kgcd32_64(a_, b_);
-    int64_t a = kabs64(a_) / gcd;
-    int64_t b = kabs64(b_) / gcd;
-
-    return a * b;
+    int64_t a = kabs64(a_);
+    int64_t b = kabs64(b_);
+    /* divide first to avoid possible overflow */
+    return (a / gcd) * b;
 }
diff --git a/src/kghelpers.h b/src/kghelpers.h
@@ -409,6 +409,7 @@ inline int32_t kabs32(int32_t a) { return a < 0? -a : a; }
 inline int64_t kabs64(int64_t a) { return a < 0? -a : a; }
 inline int32_t kmin32(int32_t a, int32_t b) { return a < b? a : b; }
 inline int32_t kmax32(int32_t a, int32_t b) { return a > b? a : b; }
+
 inline int32_t kcheck32(klisp_State *K, char *msg, int64_t i) 
 {
     if (i > (int64_t) INT32_MAX || i < (int64_t) INT32_MIN) {