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Diffstat (limited to 'src/gallium/auxiliary/gallivm/lp_bld_conv.c')
-rw-r--r--src/gallium/auxiliary/gallivm/lp_bld_conv.c218
1 files changed, 178 insertions, 40 deletions
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_conv.c b/src/gallium/auxiliary/gallivm/lp_bld_conv.c
index 8b477313d4..6967dd2622 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_conv.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_conv.c
@@ -63,6 +63,7 @@
#include "util/u_debug.h"
#include "util/u_math.h"
+#include "util/u_cpu_detect.h"
#include "lp_bld_type.h"
#include "lp_bld_const.h"
@@ -96,58 +97,104 @@ lp_build_clamped_float_to_unsigned_norm(LLVMBuilderRef builder,
LLVMTypeRef int_vec_type = lp_build_int_vec_type(src_type);
LLVMValueRef res;
unsigned mantissa;
- unsigned n;
- unsigned long long ubound;
- unsigned long long mask;
- double scale;
- double bias;
assert(src_type.floating);
+ assert(dst_width <= src_type.width);
+ src_type.sign = FALSE;
mantissa = lp_mantissa(src_type);
- /* We cannot carry more bits than the mantissa */
- n = MIN2(mantissa, dst_width);
+ if (dst_width <= mantissa) {
+ /*
+ * Apply magic coefficients that will make the desired result to appear
+ * in the lowest significant bits of the mantissa, with correct rounding.
+ *
+ * This only works if the destination width fits in the mantissa.
+ */
- /* This magic coefficients will make the desired result to appear in the
- * lowest significant bits of the mantissa.
- */
- ubound = ((unsigned long long)1 << n);
- mask = ubound - 1;
- scale = (double)mask/ubound;
- bias = (double)((unsigned long long)1 << (mantissa - n));
+ unsigned long long ubound;
+ unsigned long long mask;
+ double scale;
+ double bias;
- res = LLVMBuildFMul(builder, src, lp_build_const_vec(src_type, scale), "");
- res = LLVMBuildFAdd(builder, res, lp_build_const_vec(src_type, bias), "");
- res = LLVMBuildBitCast(builder, res, int_vec_type, "");
+ ubound = (1ULL << dst_width);
+ mask = ubound - 1;
+ scale = (double)mask/ubound;
+ bias = (double)(1ULL << (mantissa - dst_width));
- if(dst_width > n) {
- int shift = dst_width - n;
- res = LLVMBuildShl(builder, res, lp_build_const_int_vec(src_type, shift), "");
+ res = LLVMBuildFMul(builder, src, lp_build_const_vec(src_type, scale), "");
+ res = LLVMBuildFAdd(builder, res, lp_build_const_vec(src_type, bias), "");
+ res = LLVMBuildBitCast(builder, res, int_vec_type, "");
+ res = LLVMBuildAnd(builder, res, lp_build_const_int_vec(src_type, mask), "");
+ }
+ else if (dst_width == (mantissa + 1)) {
+ /*
+ * The destination width matches exactly what can be represented in
+ * floating point (i.e., mantissa + 1 bits). So do a straight
+ * multiplication followed by casting. No further rounding is necessary.
+ */
+
+ double scale;
- /* TODO: Fill in the empty lower bits for additional precision? */
- /* YES: this fixes progs/trivial/tri-z-eq.c.
- * Otherwise vertex Z=1.0 values get converted to something like
- * 0xfffffb00 and the test for equality with 0xffffffff fails.
+ scale = (double)((1ULL << dst_width) - 1);
+
+ res = LLVMBuildFMul(builder, src, lp_build_const_vec(src_type, scale), "");
+ res = LLVMBuildFPToSI(builder, res, int_vec_type, "");
+ }
+ else {
+ /*
+ * The destination exceeds what can be represented in the floating point.
+ * So multiply by the largest power two we get away with, and when
+ * subtract the most significant bit to rescale to normalized values.
+ *
+ * The largest power of two factor we can get away is
+ * (1 << (src_type.width - 1)), because we need to use signed . In theory it
+ * should be (1 << (src_type.width - 2)), but IEEE 754 rules states
+ * INT_MIN should be returned in FPToSI, which is the correct result for
+ * values near 1.0!
+ *
+ * This means we get (src_type.width - 1) correct bits for values near 0.0,
+ * and (mantissa + 1) correct bits for values near 1.0. Equally or more
+ * important, we also get exact results for 0.0 and 1.0.
*/
-#if 0
- {
- LLVMValueRef msb;
- msb = LLVMBuildLShr(builder, res, lp_build_const_int_vec(src_type, dst_width - 1), "");
- msb = LLVMBuildShl(builder, msb, lp_build_const_int_vec(src_type, shift), "");
- msb = LLVMBuildSub(builder, msb, lp_build_const_int_vec(src_type, 1), "");
- res = LLVMBuildOr(builder, res, msb, "");
- }
-#elif 0
- while(shift > 0) {
- res = LLVMBuildOr(builder, res, LLVMBuildLShr(builder, res, lp_build_const_int_vec(src_type, n), ""), "");
- shift -= n;
- n *= 2;
+
+ unsigned n = MIN2(src_type.width - 1, dst_width);
+
+ double scale = (double)(1ULL << n);
+ unsigned lshift = dst_width - n;
+ unsigned rshift = n;
+ LLVMValueRef lshifted;
+ LLVMValueRef rshifted;
+
+ res = LLVMBuildFMul(builder, src, lp_build_const_vec(src_type, scale), "");
+ res = LLVMBuildFPToSI(builder, res, int_vec_type, "");
+
+ /*
+ * Align the most significant bit to its final place.
+ *
+ * This will cause 1.0 to overflow to 0, but the later adjustment will
+ * get it right.
+ */
+ if (lshift) {
+ lshifted = LLVMBuildShl(builder, res,
+ lp_build_const_int_vec(src_type, lshift), "");
+ } else {
+ lshifted = res;
}
-#endif
+
+ /*
+ * Align the most significant bit to the right.
+ */
+ rshifted = LLVMBuildAShr(builder, res,
+ lp_build_const_int_vec(src_type, rshift), "");
+
+ /*
+ * Subtract the MSB to the LSB, therefore re-scaling from
+ * (1 << dst_width) to ((1 << dst_width) - 1).
+ */
+
+ res = LLVMBuildSub(builder, lshifted, rshifted, "");
}
- else
- res = LLVMBuildAnd(builder, res, lp_build_const_int_vec(src_type, mask), "");
return res;
}
@@ -177,6 +224,16 @@ lp_build_unsigned_norm_to_float(LLVMBuilderRef builder,
assert(dst_type.floating);
+ /* Special-case int8->float, though most cases could be handled
+ * this way:
+ */
+ if (src_width == 8) {
+ scale = 1.0/255.0;
+ res = LLVMBuildSIToFP(builder, src, vec_type, "");
+ res = LLVMBuildFMul(builder, res, lp_build_const_vec(dst_type, scale), "");
+ return res;
+ }
+
mantissa = lp_mantissa(dst_type);
n = MIN2(mantissa, src_width);
@@ -241,6 +298,87 @@ lp_build_conv(LLVMBuilderRef builder,
}
num_tmps = num_srcs;
+
+ /* Special case 4x4f --> 1x16ub
+ */
+ if (src_type.floating == 1 &&
+ src_type.fixed == 0 &&
+ src_type.sign == 1 &&
+ src_type.norm == 0 &&
+ src_type.width == 32 &&
+ src_type.length == 4 &&
+
+ dst_type.floating == 0 &&
+ dst_type.fixed == 0 &&
+ dst_type.sign == 0 &&
+ dst_type.norm == 1 &&
+ dst_type.width == 8 &&
+ dst_type.length == 16 &&
+
+ util_cpu_caps.has_sse2)
+ {
+ int i;
+
+ for (i = 0; i < num_dsts; i++, src += 4) {
+ struct lp_type int16_type = dst_type;
+ struct lp_type int32_type = dst_type;
+ LLVMValueRef lo, hi;
+ LLVMValueRef src_int0;
+ LLVMValueRef src_int1;
+ LLVMValueRef src_int2;
+ LLVMValueRef src_int3;
+ LLVMTypeRef int16_vec_type;
+ LLVMTypeRef int32_vec_type;
+ LLVMTypeRef src_vec_type;
+ LLVMTypeRef dst_vec_type;
+ LLVMValueRef const_255f;
+ LLVMValueRef a, b, c, d;
+
+ int16_type.width *= 2;
+ int16_type.length /= 2;
+ int16_type.sign = 1;
+
+ int32_type.width *= 4;
+ int32_type.length /= 4;
+ int32_type.sign = 1;
+
+ src_vec_type = lp_build_vec_type(src_type);
+ dst_vec_type = lp_build_vec_type(dst_type);
+ int16_vec_type = lp_build_vec_type(int16_type);
+ int32_vec_type = lp_build_vec_type(int32_type);
+
+ const_255f = lp_build_const_vec(src_type, 255.0f);
+
+ a = LLVMBuildFMul(builder, src[0], const_255f, "");
+ b = LLVMBuildFMul(builder, src[1], const_255f, "");
+ c = LLVMBuildFMul(builder, src[2], const_255f, "");
+ d = LLVMBuildFMul(builder, src[3], const_255f, "");
+
+ {
+ struct lp_build_context bld;
+
+ bld.builder = builder;
+ bld.type = src_type;
+ bld.vec_type = src_vec_type;
+ bld.int_elem_type = lp_build_elem_type(int32_type);
+ bld.int_vec_type = int32_vec_type;
+ bld.undef = lp_build_undef(src_type);
+ bld.zero = lp_build_zero(src_type);
+ bld.one = lp_build_one(src_type);
+
+ src_int0 = lp_build_iround(&bld, a);
+ src_int1 = lp_build_iround(&bld, b);
+ src_int2 = lp_build_iround(&bld, c);
+ src_int3 = lp_build_iround(&bld, d);
+ }
+ /* relying on clamping behavior of sse2 intrinsics here */
+ lo = lp_build_pack2(builder, int32_type, int16_type, src_int0, src_int1);
+ hi = lp_build_pack2(builder, int32_type, int16_type, src_int2, src_int3);
+ dst[i] = lp_build_pack2(builder, int16_type, dst_type, lo, hi);
+ }
+ return;
+ }
+
/*
* Clamp if necessary
*/
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-22 11:15:16 +0000