diff --git a/source/lib/res/graphics/ogl_tex.cpp b/source/lib/res/graphics/ogl_tex.cpp
index 79a7291aaa..3698a1c7ca 100644
--- a/source/lib/res/graphics/ogl_tex.cpp
+++ b/source/lib/res/graphics/ogl_tex.cpp
@@ -749,7 +749,7 @@ struct UploadParams
 };
 
 static void upload_level(uint level, uint level_w, uint level_h,
-	const u8* restrict level_data, size_t UNUSED(level_data_size), void* restrict ctx)
+	const u8* RESTRICT level_data, size_t UNUSED(level_data_size), void* RESTRICT ctx)
 {
 	const UploadParams* up = (const UploadParams*)ctx;
 	glTexImage2D(GL_TEXTURE_2D, level, up->int_fmt, level_w, level_h, 0,
@@ -757,7 +757,7 @@ static void upload_level(uint level, uint level_w, uint level_h,
 }
 
 static void upload_compressed_level(uint level, uint level_w, uint level_h,
-	const u8* restrict level_data, size_t level_data_size, void* restrict ctx)
+	const u8* RESTRICT level_data, size_t level_data_size, void* RESTRICT ctx)
 {
 	const UploadParams* up = (const UploadParams*)ctx;
 	pglCompressedTexImage2DARB(GL_TEXTURE_2D, level, up->fmt,
diff --git a/source/lib/res/graphics/tex.cpp b/source/lib/res/graphics/tex.cpp
index e4fd97ecc1..ba88ac67ef 100644
--- a/source/lib/res/graphics/tex.cpp
+++ b/source/lib/res/graphics/tex.cpp
@@ -123,8 +123,8 @@ LibError tex_validate_plain_format(uint bpp, uint flags)
 // mipmaps
 //-----------------------------------------------------------------------------
 
-void tex_util_foreach_mipmap(uint w, uint h, uint bpp, const u8* restrict data,
-	int levels_to_skip, uint data_padding, MipmapCB cb, void* restrict ctx)
+void tex_util_foreach_mipmap(uint w, uint h, uint bpp, const u8* RESTRICT data,
+	int levels_to_skip, uint data_padding, MipmapCB cb, void* RESTRICT ctx)
 {
 	uint level_w = w, level_h = h;
 	const u8* level_data = data;
@@ -179,7 +179,7 @@ struct CreateLevelData
 
 // uses 2x2 box filter
 static void create_level(uint level, uint level_w, uint level_h,
-	const u8* restrict level_data, size_t level_data_size, void* restrict ctx)
+	const u8* RESTRICT level_data, size_t level_data_size, void* RESTRICT ctx)
 {
 	CreateLevelData* cld = (CreateLevelData*)ctx;
 	const size_t src_w = cld->prev_level_w;
@@ -578,7 +578,7 @@ u8* tex_get_data(const Tex* t)
 
 
 static void add_level_size(uint UNUSED(level), uint UNUSED(level_w), uint UNUSED(level_h),
-	const u8* restrict UNUSED(level_data), size_t level_data_size, void* restrict ctx)
+	const u8* RESTRICT UNUSED(level_data), size_t level_data_size, void* RESTRICT ctx)
 {
 	size_t* ptotal_size = (size_t*)ctx;
 	*ptotal_size += level_data_size;
diff --git a/source/lib/res/graphics/tex.h b/source/lib/res/graphics/tex.h
index 0b223bca2b..c5422ccc31 100644
--- a/source/lib/res/graphics/tex.h
+++ b/source/lib/res/graphics/tex.h
@@ -371,7 +371,7 @@ const int TEX_BASE_LEVEL_ONLY = -1;
  * @param ctx passed through from tex_util_foreach_mipmap.
  **/
 typedef void (*MipmapCB)(uint level, uint level_w, uint level_h,
-	const u8* level_data, size_t level_data_size, void* ctx);
+	const u8* RESTRICT level_data, size_t level_data_size, void* RESTRICT ctx);
 
 /**
  * for a series of mipmaps stored from base to highest, call back for
@@ -390,8 +390,8 @@ typedef void (*MipmapCB)(uint level, uint level_w, uint level_h,
  * @param cb MipmapCB to call
  * @param ctx extra data to pass to cb
  **/
-extern void tex_util_foreach_mipmap(uint w, uint h, uint bpp, const u8* restrict data,
-	int levels_to_skip, uint data_padding, MipmapCB cb, void* restrict ctx);
+extern void tex_util_foreach_mipmap(uint w, uint h, uint bpp, const u8* RESTRICT data,
+	int levels_to_skip, uint data_padding, MipmapCB cb, void* RESTRICT ctx);
 
 
 //
diff --git a/source/lib/res/graphics/tex_bmp.cpp b/source/lib/res/graphics/tex_bmp.cpp
index 6609b0a9d3..e5e7ef154c 100644
--- a/source/lib/res/graphics/tex_bmp.cpp
+++ b/source/lib/res/graphics/tex_bmp.cpp
@@ -91,7 +91,7 @@ static size_t bmp_hdr_size(const u8* file)
 
 
 // requirements: uncompressed, direct colour, bottom up
-static LibError bmp_decode(DynArray* restrict da, Tex* restrict t)
+static LibError bmp_decode(DynArray* RESTRICT da, Tex* RESTRICT t)
 {
 	u8* file         = da->base;
 
@@ -122,7 +122,7 @@ static LibError bmp_decode(DynArray* restrict da, Tex* restrict t)
 }
 
 
-static LibError bmp_encode(Tex* restrict t, DynArray* restrict da)
+static LibError bmp_encode(Tex* RESTRICT t, DynArray* RESTRICT da)
 {
 	const size_t hdr_size = sizeof(BmpHeader);	// needed for BITMAPFILEHEADER
 	const size_t img_size = tex_img_size(t);
diff --git a/source/lib/res/graphics/tex_codec.h b/source/lib/res/graphics/tex_codec.h
index 1eae9a9793..bb8e41a037 100644
--- a/source/lib/res/graphics/tex_codec.h
+++ b/source/lib/res/graphics/tex_codec.h
@@ -46,7 +46,7 @@ struct TexCodecVTbl
 	 * @param t output texture object
 	 * @return LibError
 	 **/
-	LibError (*decode)(DynArray * restrict da, Tex * restrict t);
+	LibError (*decode)(DynArray * RESTRICT da, Tex * RESTRICT t);
 
 
 	/**
@@ -60,7 +60,7 @@ struct TexCodecVTbl
 	 * by the caller.
 	 * @return LibError
 	 **/
-	LibError (*encode)(Tex * restrict t, DynArray * restrict da);
+	LibError (*encode)(Tex * RESTRICT t, DynArray * RESTRICT da);
 
 	/**
 	 * transform the texture's pixel format.
diff --git a/source/lib/res/graphics/tex_dds.cpp b/source/lib/res/graphics/tex_dds.cpp
index 97c4fa12ea..13f152f9a3 100644
--- a/source/lib/res/graphics/tex_dds.cpp
+++ b/source/lib/res/graphics/tex_dds.cpp
@@ -99,7 +99,7 @@ struct S3tcBlock
 };
 
 
-static void s3tc_precalc_alpha(uint dxt, const u8* restrict a_block, S3tcBlock* restrict b)
+static void s3tc_precalc_alpha(uint dxt, const u8* RESTRICT a_block, S3tcBlock* RESTRICT b)
 {
 	// read block contents
 	const uint a0 = a_block[0], a1 = a_block[1];
@@ -138,7 +138,7 @@ static void s3tc_precalc_alpha(uint dxt, const u8* restrict a_block, S3tcBlock*
 }
 
 
-static void s3tc_precalc_color(uint dxt, const u8* restrict c_block, S3tcBlock* restrict b)
+static void s3tc_precalc_color(uint dxt, const u8* RESTRICT c_block, S3tcBlock* RESTRICT b)
 {
 	// read block contents
 	// .. S3TC reference colors (565 format). the color table is generated
@@ -175,7 +175,7 @@ static void s3tc_precalc_color(uint dxt, const u8* restrict c_block, S3tcBlock*
 }
 
 
-static void s3tc_precalc_block(uint dxt, const u8* restrict block, S3tcBlock* restrict b)
+static void s3tc_precalc_block(uint dxt, const u8* RESTRICT block, S3tcBlock* RESTRICT b)
 {
 	b->dxt = dxt;
 
@@ -188,7 +188,7 @@ static void s3tc_precalc_block(uint dxt, const u8* restrict block, S3tcBlock* re
 }
 
 
-static void s3tc_write_pixel(const S3tcBlock* restrict b, uint pixel_idx, u8* restrict out)
+static void s3tc_write_pixel(const S3tcBlock* RESTRICT b, uint pixel_idx, u8* RESTRICT out)
 {
 	debug_assert(pixel_idx < 16);
 
@@ -231,7 +231,7 @@ struct S3tcDecompressInfo
 };
 
 static void s3tc_decompress_level(uint UNUSED(level), uint level_w, uint level_h,
-	const u8* restrict level_data, size_t level_data_size, void* restrict ctx)
+	const u8* RESTRICT level_data, size_t level_data_size, void* RESTRICT ctx)
 {
 	S3tcDecompressInfo* di = (S3tcDecompressInfo*)ctx;
 	const uint dxt             = di->dxt;
@@ -615,7 +615,7 @@ static size_t dds_hdr_size(const u8* UNUSED(file))
 }
 
 
-static LibError dds_decode(DynArray* restrict da, Tex* restrict t)
+static LibError dds_decode(DynArray* RESTRICT da, Tex* RESTRICT t)
 {
 	u8* file         = da->base;
 	const DDSURFACEDESC2* sd = (const DDSURFACEDESC2*)(file+4);
@@ -633,7 +633,7 @@ static LibError dds_decode(DynArray* restrict da, Tex* restrict t)
 }
 
 
-static LibError dds_encode(Tex* restrict UNUSED(t), DynArray* restrict UNUSED(da))
+static LibError dds_encode(Tex* RESTRICT UNUSED(t), DynArray* RESTRICT UNUSED(da))
 {
 	// note: do not return ERR::NOT_IMPLEMENTED et al. because that would
 	// break tex_write (which assumes either this, 0 or errors are returned).
diff --git a/source/lib/res/graphics/tex_jpg.cpp b/source/lib/res/graphics/tex_jpg.cpp
index 590fad9f21..8e1f781a80 100644
--- a/source/lib/res/graphics/tex_jpg.cpp
+++ b/source/lib/res/graphics/tex_jpg.cpp
@@ -589,7 +589,7 @@ static size_t jpg_hdr_size(const u8* UNUSED(file))
 }
 
 
-static LibError jpg_decode(DynArray* restrict da, Tex* restrict t)
+static LibError jpg_decode(DynArray* RESTRICT da, Tex* RESTRICT t)
 {
 	LibError err;
 
@@ -628,7 +628,7 @@ fail:
 
 
 // limitation: palette images aren't supported
-static LibError jpg_encode(Tex* restrict t, DynArray* restrict da)
+static LibError jpg_encode(Tex* RESTRICT t, DynArray* RESTRICT da)
 {
 	LibError err;
 
diff --git a/source/lib/res/graphics/tex_png.cpp b/source/lib/res/graphics/tex_png.cpp
index 328dce34f1..e07f68bf39 100644
--- a/source/lib/res/graphics/tex_png.cpp
+++ b/source/lib/res/graphics/tex_png.cpp
@@ -217,7 +217,7 @@ static size_t png_hdr_size(const u8* UNUSED(file))
 TIMER_ADD_CLIENT(tc_png_decode);
 
 // limitation: palette images aren't supported
-static LibError png_decode(DynArray* restrict da, Tex* restrict t)
+static LibError png_decode(DynArray* RESTRICT da, Tex* RESTRICT t)
 {
 TIMER_ACCRUE(tc_png_decode);
 
@@ -260,7 +260,7 @@ ret:
 
 
 // limitation: palette images aren't supported
-static LibError png_encode(Tex* restrict t, DynArray* restrict da)
+static LibError png_encode(Tex* RESTRICT t, DynArray* RESTRICT da)
 {
 	LibError err  = ERR::FAIL;
 	// freed when ret is reached:
diff --git a/source/lib/res/graphics/tex_tga.cpp b/source/lib/res/graphics/tex_tga.cpp
index b4380e410d..ec1d1fd61b 100644
--- a/source/lib/res/graphics/tex_tga.cpp
+++ b/source/lib/res/graphics/tex_tga.cpp
@@ -108,7 +108,7 @@ static size_t tga_hdr_size(const u8* file)
 
 
 // requirements: uncompressed, direct colour, bottom up
-static LibError tga_decode(DynArray* restrict da, Tex* restrict t)
+static LibError tga_decode(DynArray* RESTRICT da, Tex* RESTRICT t)
 {
 	u8* file         = da->base;
 
@@ -142,7 +142,7 @@ static LibError tga_decode(DynArray* restrict da, Tex* restrict t)
 }
 
 
-static LibError tga_encode(Tex* restrict t, DynArray* restrict da)
+static LibError tga_encode(Tex* RESTRICT t, DynArray* RESTRICT da)
 {
 	u8 img_desc = 0;
 	if(t->flags & TEX_TOP_DOWN)
diff --git a/source/lib/sysdep/sysdep.h b/source/lib/sysdep/sysdep.h
index a4b78ed69c..8cb135e093 100644
--- a/source/lib/sysdep/sysdep.h
+++ b/source/lib/sysdep/sysdep.h
@@ -153,17 +153,37 @@ extern void* alloca(size_t size);
 # endif
 #endif
 
-// C99 restrict
+// C99-like restrict (non-standard in C++, but widely supported in various forms).
+// Must only be used on pointers - some compilers (g++) support it on references
+// and member functions, but not all do (and we want to work on as many as possible).
+//
+// We call this "RESTRICT" to avoid conflicts with VC's __declspec(restrict),
+// and because it's not really the same as C99's restrict.
+//
+// To be safe and satisfy the compilers' stated requirements: an object accessed
+// by a restricted pointer must not be accessed by any other pointer within the
+// lifetime of the restricted pointer, if the object is modified.
+// To maximise the chance of optimisation, any pointers that could potentially
+// alias with the restricted one should be marked as restricted too.
+//
 // .. for some reason, g++-3.3 claims to support C99 (according to
 //    __STDC_VERSION__) but doesn't have the restrict keyword.
 //    use the extension __restrict__ instead.
 #if GCC_VERSION
-# define restrict __restrict__
-// .. already available; need do nothing
+# define RESTRICT __restrict__
+// .. already available as 'restrict'
 #elif HAVE_C99
+# define RESTRICT restrict
+// .. ICC provides restrict, though you have to make sure you pass /Qrestrict
+// (-restrict on Linux) in the compiler options
+#elif ICC_VERSION
+# define RESTRICT restrict
+// .. VC8 provides __restrict
+#elif MSC_VERSION >= 800
+# define RESTRICT __restrict
 // .. unsupported; remove it from code
 #else
-# define restrict
+# define RESTRICT
 #endif
 
 // C99 __func__