ceil/floor in sse simd

Can anyone suggest a fast way to compute float floor/ceil using pre-SSE4.1 SIMD? I need to correctly handle all the corner cases, e.g. when I have a float value, that is not representable by 32-bit int.

Currently I'm using similar to the following code (I use C intrinsics, converted to asm for clarity):

;make many copies of the data
movaps       xmm0,   [float_value]
movaps       xmm1,   xmm0
movaps       xmm2,   xmm0

;check if the value is not too large in magnitude
andps        xmm1,   [exp_mask]
pcmpgtd      xmm1,   [max_exp]

;calculate the floor()
cvttps2dq    xmm3,   xmm2
psrld        xmm2,   31
psubd        xmm3,   xmm2
cvtsq2ps     xmm2,   xmm3

;combine the results
andps        xmm0,   xmm1
andnps       xmm1,   xmm2
orps         xmm0,   xmm1

Is there a more effici开发者_开发问答ent way to check if the float value is not too large for 32bit int?

Here is some pseudocode for a single element that should be directly convertible into vector instructions:

float f;
int i = (int)f; /* 0x80000000 if out of range (as from cvtps2dq) */
if (i == 0x80000000)
    return f;
else
    return (float)i;

You would use your rounding mode for the cast to int in the second line. You can also test the IE flag in MXCSR to detect out of range values.