diff --git a/idlib/math/Simd_SSE.cpp b/idlib/math/Simd_SSE.cpp
index 286ebe7..4c5917c 100644
--- a/idlib/math/Simd_SSE.cpp
+++ b/idlib/math/Simd_SSE.cpp
@@ -40,19 +40,18 @@ If you have questions concerning this license or the applicable additional terms
 //                                                        E
 //===============================================================
 
+#define DRAWVERT_SIZE				60
+#define DRAWVERT_XYZ_OFFSET			(ptrdiff_t(src) - ptrdiff_t(&src->xyz))
+#define DRAWVERT_ST_OFFSET			(ptrdiff_t(src) - ptrdiff_t(&src->st))
+#define DRAWVERT_NORMAL_OFFSET		(ptrdiff_t(src) - ptrdiff_t(&src->normal))
+#define DRAWVERT_TANGENT0_OFFSET	(ptrdiff_t(src) - ptrdiff_t(&src->tangents[0]))
+#define DRAWVERT_TANGENT1_OFFSET	(ptrdiff_t(src) - ptrdiff_t(&src->tangents[1]))
+#define DRAWVERT_COLOR_OFFSET		(ptrdiff_t(src) - ptrdiff_t(&src->color))
 
 #if defined(MACOS_X) && defined(__i386__)
 
 #include <xmmintrin.h>
 
-#define DRAWVERT_SIZE				60
-#define DRAWVERT_XYZ_OFFSET			(0*4)
-#define DRAWVERT_ST_OFFSET			(3*4)
-#define DRAWVERT_NORMAL_OFFSET		(5*4)
-#define DRAWVERT_TANGENT0_OFFSET	(8*4)
-#define DRAWVERT_TANGENT1_OFFSET	(11*4)
-#define DRAWVERT_COLOR_OFFSET		(14*4)
-
 #define SHUFFLEPS( x, y, z, w )		(( (x) & 3 ) << 6 | ( (y) & 3 ) << 4 | ( (z) & 3 ) << 2 | ( (w) & 3 ))
 #define R_SHUFFLEPS( x, y, z, w )	(( (w) & 3 ) << 6 | ( (z) & 3 ) << 4 | ( (y) & 3 ) << 2 | ( (x) & 3 ))
 
@@ -93,7 +92,6 @@ void VPCALL idSIMD_SSE::Dot( float *dst, const idPlane &constant, const idDrawVe
 	char *dst_p = (char *) dst;                             // dst_p = ecx
 
 	assert( sizeof( idDrawVert ) == DRAWVERT_SIZE );
-	assert( (int)&((idDrawVert *)0)->xyz == DRAWVERT_XYZ_OFFSET );
 
 	/*
 		and			eax, ~3
@@ -256,7 +254,6 @@ idSIMD_SSE::MinMax
 void VPCALL idSIMD_SSE::MinMax( idVec3 &min, idVec3 &max, const idDrawVert *src, const int *indexes, const int count ) {
 
 	assert( sizeof( idDrawVert ) == DRAWVERT_SIZE );
-	assert( (int)&((idDrawVert *)0)->xyz == DRAWVERT_XYZ_OFFSET );
 
 	__m128 xmm0, xmm1, xmm2, xmm3, xmm4, xmm5, xmm6, xmm7;
 	char *indexes_p;
@@ -998,12 +995,6 @@ void VPCALL idSIMD_SSE::Dot( float *dst, const idVec3 &constant, const idPlane *
 
 
 #define DRAWVERT_SIZE				60
-#define DRAWVERT_XYZ_OFFSET			(0*4)
-#define DRAWVERT_ST_OFFSET			(3*4)
-#define DRAWVERT_NORMAL_OFFSET		(5*4)
-#define DRAWVERT_TANGENT0_OFFSET	(8*4)
-#define DRAWVERT_TANGENT1_OFFSET	(11*4)
-#define DRAWVERT_COLOR_OFFSET		(14*4)
 
 #define JOINTQUAT_SIZE				(7*4)
 #define JOINTMAT_SIZE				(4*3*4)
diff --git a/idlib/math/Simd_SSE2.cpp b/idlib/math/Simd_SSE2.cpp
index 6bb89c0..639de48 100644
--- a/idlib/math/Simd_SSE2.cpp
+++ b/idlib/math/Simd_SSE2.cpp
@@ -76,7 +76,7 @@ void VPCALL idSIMD_SSE2::CmpLT( byte *dst, const byte bitNum, const float *src0,
 	int dst_l;
 
 	/* if the float array is not aligned on a 4 byte boundary */
-	if ( ((int) src0) & 3 ) {
+	if ( ptrdiff_t(src0) & 3 ) {
 		/* unaligned memory access */
 		pre = 0;
 		cnt = count >> 2;
@@ -152,8 +152,8 @@ void VPCALL idSIMD_SSE2::CmpLT( byte *dst, const byte bitNum, const float *src0,
 	}
 	else {
 		/* aligned memory access */
-		aligned = (float *) ((((int) src0) + 15) & ~15);
-		if ( (int)aligned > ((int)src0) + count ) {
+		aligned = (float *) ((ptrdiff_t(src0) + 15) & ~15);
+		if ( ptrdiff_t(aligned) > ptrdiff_t(src0) + count ) {
 			pre = count;
 			post = 0;
 		}