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path: root/drivers/gpu/drm/radeon/r600_blit.c
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Diffstat (limited to 'drivers/gpu/drm/radeon/r600_blit.c')
-rw-r--r--drivers/gpu/drm/radeon/r600_blit.c115
1 files changed, 60 insertions, 55 deletions
diff --git a/drivers/gpu/drm/radeon/r600_blit.c b/drivers/gpu/drm/radeon/r600_blit.c
index 26ace5623dc7..77da1f9c0b8e 100644
--- a/drivers/gpu/drm/radeon/r600_blit.c
+++ b/drivers/gpu/drm/radeon/r600_blit.c
@@ -488,31 +488,36 @@ set_default_state(drm_radeon_private_t *dev_priv)
ADVANCE_RING();
}
-static uint32_t i2f(uint32_t input)
+/* 23 bits of float fractional data */
+#define I2F_FRAC_BITS 23
+#define I2F_MASK ((1 << I2F_FRAC_BITS) - 1)
+
+/*
+ * Converts unsigned integer into 32-bit IEEE floating point representation.
+ * Will be exact from 0 to 2^24. Above that, we round towards zero
+ * as the fractional bits will not fit in a float. (It would be better to
+ * round towards even as the fpu does, but that is slower.)
+ */
+__pure uint32_t int2float(uint32_t x)
{
- u32 result, i, exponent, fraction;
-
- if ((input & 0x3fff) == 0)
- result = 0; /* 0 is a special case */
- else {
- exponent = 140; /* exponent biased by 127; */
- fraction = (input & 0x3fff) << 10; /* cheat and only
- handle numbers below 2^^15 */
- for (i = 0; i < 14; i++) {
- if (fraction & 0x800000)
- break;
- else {
- fraction = fraction << 1; /* keep
- shifting left until top bit = 1 */
- exponent = exponent - 1;
- }
- }
- result = exponent << 23 | (fraction & 0x7fffff); /* mask
- off top bit; assumed 1 */
- }
- return result;
-}
+ uint32_t msb, exponent, fraction;
+
+ /* Zero is special */
+ if (!x) return 0;
+
+ /* Get location of the most significant bit */
+ msb = __fls(x);
+ /*
+ * Use a rotate instead of a shift because that works both leftwards
+ * and rightwards due to the mod(32) behaviour. This means we don't
+ * need to check to see if we are above 2^24 or not.
+ */
+ fraction = ror32(x, (msb - I2F_FRAC_BITS) & 0x1f) & I2F_MASK;
+ exponent = (127 + msb) << I2F_FRAC_BITS;
+
+ return fraction + exponent;
+}
static int r600_nomm_get_vb(struct drm_device *dev)
{
@@ -631,20 +636,20 @@ r600_blit_copy(struct drm_device *dev,
vb = r600_nomm_get_vb_ptr(dev);
}
- vb[0] = i2f(dst_x);
+ vb[0] = int2float(dst_x);
vb[1] = 0;
- vb[2] = i2f(src_x);
+ vb[2] = int2float(src_x);
vb[3] = 0;
- vb[4] = i2f(dst_x);
- vb[5] = i2f(h);
- vb[6] = i2f(src_x);
- vb[7] = i2f(h);
+ vb[4] = int2float(dst_x);
+ vb[5] = int2float(h);
+ vb[6] = int2float(src_x);
+ vb[7] = int2float(h);
- vb[8] = i2f(dst_x + cur_size);
- vb[9] = i2f(h);
- vb[10] = i2f(src_x + cur_size);
- vb[11] = i2f(h);
+ vb[8] = int2float(dst_x + cur_size);
+ vb[9] = int2float(h);
+ vb[10] = int2float(src_x + cur_size);
+ vb[11] = int2float(h);
/* src */
set_tex_resource(dev_priv, FMT_8,
@@ -720,20 +725,20 @@ r600_blit_copy(struct drm_device *dev,
vb = r600_nomm_get_vb_ptr(dev);
}
- vb[0] = i2f(dst_x / 4);
+ vb[0] = int2float(dst_x / 4);
vb[1] = 0;
- vb[2] = i2f(src_x / 4);
+ vb[2] = int2float(src_x / 4);
vb[3] = 0;
- vb[4] = i2f(dst_x / 4);
- vb[5] = i2f(h);
- vb[6] = i2f(src_x / 4);
- vb[7] = i2f(h);
+ vb[4] = int2float(dst_x / 4);
+ vb[5] = int2float(h);
+ vb[6] = int2float(src_x / 4);
+ vb[7] = int2float(h);
- vb[8] = i2f((dst_x + cur_size) / 4);
- vb[9] = i2f(h);
- vb[10] = i2f((src_x + cur_size) / 4);
- vb[11] = i2f(h);
+ vb[8] = int2float((dst_x + cur_size) / 4);
+ vb[9] = int2float(h);
+ vb[10] = int2float((src_x + cur_size) / 4);
+ vb[11] = int2float(h);
/* src */
set_tex_resource(dev_priv, FMT_8_8_8_8,
@@ -803,20 +808,20 @@ r600_blit_swap(struct drm_device *dev,
dx2 = dx + w;
dy2 = dy + h;
- vb[0] = i2f(dx);
- vb[1] = i2f(dy);
- vb[2] = i2f(sx);
- vb[3] = i2f(sy);
+ vb[0] = int2float(dx);
+ vb[1] = int2float(dy);
+ vb[2] = int2float(sx);
+ vb[3] = int2float(sy);
- vb[4] = i2f(dx);
- vb[5] = i2f(dy2);
- vb[6] = i2f(sx);
- vb[7] = i2f(sy2);
+ vb[4] = int2float(dx);
+ vb[5] = int2float(dy2);
+ vb[6] = int2float(sx);
+ vb[7] = int2float(sy2);
- vb[8] = i2f(dx2);
- vb[9] = i2f(dy2);
- vb[10] = i2f(sx2);
- vb[11] = i2f(sy2);
+ vb[8] = int2float(dx2);
+ vb[9] = int2float(dy2);
+ vb[10] = int2float(sx2);
+ vb[11] = int2float(sy2);
switch(cpp) {
case 4:
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