diff --git a/docs/ispc.txt b/docs/ispc.txt
index 5d9ea2b0..32e5017c 100644
--- a/docs/ispc.txt
+++ b/docs/ispc.txt
@@ -1247,6 +1247,18 @@ Here are three ways of specifying the integer value "15":
    int fifteen_hex     = 0xf;
    int fifteen_binary  = 0b1111;
 
+A number of suffixes can be provided with integer numeric constants.
+First, "u" denotes that the constant is unsigned, and "ll" denotes a 64-bit
+integer constant (while "l" denotes a 32-bit integer constant).  It is also
+possible to denote units of 1024, 1024*1024, or 1024*1024*1024 with the
+SI-inspired suffixes "k", "M", and "G" respectively:
+
+::
+
+   int two_kb = 2k;   // 2048
+   int two_megs = 2M; // 2 * 1024 * 1024
+   int one_gig = 1G;  // 1024 * 1024 * 1024
+
 Floating-point constants can be specified in one of three ways.  First,
 they may be a sequence of zero or more digits from 0 to 9, followed by a
 period, followed by zero or more digits from 0 to 9. (There must be at
diff --git a/lex.ll b/lex.ll
index f4161c94..39194767 100644
--- a/lex.ll
+++ b/lex.ll
@@ -42,7 +42,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 
-static uint64_t lParseBinary(const char *ptr, SourcePos pos);
+static uint64_t lParseBinary(const char *ptr, SourcePos pos, char **endPtr);
 static void lCComment(SourcePos *);
 static void lCppComment(SourcePos *);
 static void lHandleCppHash(SourcePos *);
@@ -67,7 +67,7 @@ inline int isatty(int) { return 0; }
 %option nounistd
 
 WHITESPACE [ \t\r]+
-INT_NUMBER (([0-9]+)|(0x[0-9a-fA-F]+)|(0b[01]+))
+INT_NUMBER (([0-9]+)|(0x[0-9a-fA-F]+)|(0b[01]+))[kMG]?
 FLOAT_NUMBER (([0-9]+|(([0-9]+\.[0-9]*[fF]?)|(\.[0-9]+)))([eE][-+]?[0-9]+)?[fF]?)
 HEX_FLOAT_NUMBER (0x[01](\.[0-9a-fA-F]*)?p[-+]?[0-9]+[fF]?)
 
@@ -151,11 +151,10 @@ L?\"(\\.|[^\\"])*\" { lStringConst(yylval, yylloc); return TOKEN_STRING_LITERAL;
 {INT_NUMBER}+(u|U|l|L)*? { 
     int ls = 0, us = 0;
 
+    char *endPtr = NULL;
     if (yytext[0] == '0' && yytext[1] == 'b')
-        yylval->intVal = lParseBinary(yytext+2, *yylloc);
+        yylval->intVal = lParseBinary(yytext+2, *yylloc, &endPtr);
     else {
-        char *endPtr = NULL;
-
 #ifdef ISPC_IS_WINDOWS
         yylval->intVal = _strtoi64(yytext, &endPtr, 0);
 #else
@@ -163,18 +162,33 @@ L?\"(\\.|[^\\"])*\" { lStringConst(yylval, yylloc); return TOKEN_STRING_LITERAL;
         // fit into 64 bits...
         yylval->intVal = strtoull(yytext, &endPtr, 0);
 #endif
-        for (; *endPtr; endPtr++) {
-           if (*endPtr == 'l' || *endPtr == 'L')
-                ls++;
-           else if (*endPtr == 'u' || *endPtr == 'U')
-                us++;
-        }
-        if (ls >= 2)
-            return us ? TOKEN_UINT64_CONSTANT : TOKEN_INT64_CONSTANT;
-        else if (ls == 1)
-           return us ? TOKEN_UINT32_CONSTANT : TOKEN_INT32_CONSTANT;
     }
 
+    bool kilo = false, mega = false, giga = false;
+    for (; *endPtr; endPtr++) {
+        if (*endPtr == 'k')
+            kilo = true;
+        else if (*endPtr == 'M')
+            mega = true;
+        else if (*endPtr == 'G')
+            giga = true;        
+        else if (*endPtr == 'l' || *endPtr == 'L')
+            ls++;
+        else if (*endPtr == 'u' || *endPtr == 'U')
+            us++;
+    }
+    if (kilo)
+        yylval->intVal *= 1024;
+    if (mega)
+        yylval->intVal *= 1024*1024;
+    if (giga)
+        yylval->intVal *= 1024*1024*1024;
+
+    if (ls >= 2)
+        return us ? TOKEN_UINT64_CONSTANT : TOKEN_INT64_CONSTANT;
+    else if (ls == 1)
+        return us ? TOKEN_UINT32_CONSTANT : TOKEN_INT32_CONSTANT;
+
     // See if we can fit this into a 32-bit integer...
     if ((yylval->intVal & 0xffffffff) == yylval->intVal)
         return us ? TOKEN_UINT32_CONSTANT : TOKEN_INT32_CONSTANT;
@@ -268,14 +282,11 @@ L?\"(\\.|[^\\"])*\" { lStringConst(yylval, yylloc); return TOKEN_STRING_LITERAL;
 /** Return the integer version of a binary constant from a string.
  */
 static uint64_t
-lParseBinary(const char *ptr, SourcePos pos) {
+lParseBinary(const char *ptr, SourcePos pos, char **endPtr) {
     uint64_t val = 0;
     bool warned = false;
 
-    while (*ptr != '\0') {
-        /* if this hits, the regexp for 0b... constants is broken */
-        Assert(*ptr == '0' || *ptr == '1');
-
+    while (*ptr == '0' || *ptr == '1') {
         if ((val & (((int64_t)1)<<63)) && warned == false) {
             // We're about to shift out a set bit
             Warning(pos, "Can't represent binary constant with a 64-bit integer type");
@@ -285,6 +296,7 @@ lParseBinary(const char *ptr, SourcePos pos) {
         val = (val << 1) | (*ptr == '0' ? 0 : 1);
         ++ptr;
     }
+    *endPtr = (char *)ptr;
     return val;
 }
 
diff --git a/tests/kilo-mega-giga-1.ispc b/tests/kilo-mega-giga-1.ispc
new file mode 100644
index 00000000..9ae8f87e
--- /dev/null
+++ b/tests/kilo-mega-giga-1.ispc
@@ -0,0 +1,13 @@
+
+export uniform int width() { return programCount; }
+
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+    float a = aFOO[programIndex]; 
+    a *= 1k;
+    RET[programIndex] = a; 
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 1024*(programIndex+1);
+}
diff --git a/tests/kilo-mega-giga-2.ispc b/tests/kilo-mega-giga-2.ispc
new file mode 100644
index 00000000..77e201ef
--- /dev/null
+++ b/tests/kilo-mega-giga-2.ispc
@@ -0,0 +1,12 @@
+
+export uniform int width() { return programCount; }
+
+
+export void f_fu(uniform float RET[], uniform float aFOO[], uniform float b) {
+    int a = b + 2M;
+    RET[programIndex] = a;
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 2*1024*1024 + 5;
+}
diff --git a/tests/kilo-mega-giga-3.ispc b/tests/kilo-mega-giga-3.ispc
new file mode 100644
index 00000000..aa80e8be
--- /dev/null
+++ b/tests/kilo-mega-giga-3.ispc
@@ -0,0 +1,14 @@
+
+export uniform int width() { return programCount; }
+
+
+export void f_fu(uniform float RET[], uniform float aFOO[], uniform float b) {
+    unsigned int32 a = 3G;
+    a -= 2G;
+    a -= 1024M;
+    RET[programIndex] = a;
+}
+
+export void result(uniform float RET[]) {
+    RET[programIndex] = 0;
+}