/**************************************************************************
*
- * Copyright 2009 VMware, Inc.
+ * Copyright 2009-2010 VMware, Inc.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
#include "lp_bld_arit.h"
+#define EXP_POLY_DEGREE 3
+
+#define LOG_POLY_DEGREE 5
+
+
/**
* Generate min(a, b)
* No checks for special case values of a or b = 1 or 0 are done.
const char *intrinsic = NULL;
LLVMValueRef cond;
+ assert(lp_check_value(type, a));
+ assert(lp_check_value(type, b));
+
/* TODO: optimize the constant case */
if(type.width * type.length == 128) {
const char *intrinsic = NULL;
LLVMValueRef cond;
+ assert(lp_check_value(type, a));
+ assert(lp_check_value(type, b));
+
/* TODO: optimize the constant case */
if(type.width * type.length == 128) {
{
const struct lp_type type = bld->type;
+ assert(lp_check_value(type, a));
+
if(a == bld->one)
return bld->zero;
if(a == bld->zero)
}
if(LLVMIsConstant(a))
- return LLVMConstSub(bld->one, a);
+ if (type.floating)
+ return LLVMConstFSub(bld->one, a);
+ else
+ return LLVMConstSub(bld->one, a);
else
- return LLVMBuildSub(bld->builder, bld->one, a, "");
+ if (type.floating)
+ return LLVMBuildFSub(bld->builder, bld->one, a, "");
+ else
+ return LLVMBuildSub(bld->builder, bld->one, a, "");
}
const struct lp_type type = bld->type;
LLVMValueRef res;
+ assert(lp_check_value(type, a));
+ assert(lp_check_value(type, b));
+
if(a == bld->zero)
return b;
if(b == bld->zero)
}
if(LLVMIsConstant(a) && LLVMIsConstant(b))
- res = LLVMConstAdd(a, b);
+ if (type.floating)
+ res = LLVMConstFAdd(a, b);
+ else
+ res = LLVMConstAdd(a, b);
else
- res = LLVMBuildAdd(bld->builder, a, b, "");
+ if (type.floating)
+ res = LLVMBuildFAdd(bld->builder, a, b, "");
+ else
+ res = LLVMBuildAdd(bld->builder, a, b, "");
/* clamp to ceiling of 1.0 */
if(bld->type.norm && (bld->type.floating || bld->type.fixed))
}
-/** Return the sum of the elements of a */
+/** Return the scalar sum of the elements of a */
LLVMValueRef
lp_build_sum_vector(struct lp_build_context *bld,
LLVMValueRef a)
LLVMValueRef index, res;
unsigned i;
- if (a == bld->zero)
- return bld->zero;
- if (a == bld->undef)
- return bld->undef;
- assert(type.length > 1);
+ assert(lp_check_value(type, a));
+
+ if (type.length == 1) {
+ return a;
+ }
assert(!bld->type.norm);
for (i = 1; i < type.length; i++) {
index = LLVMConstInt(LLVMInt32Type(), i, 0);
- res = LLVMBuildAdd(bld->builder, res,
- LLVMBuildExtractElement(bld->builder, a, index, ""),
- "");
+ if (type.floating)
+ res = LLVMBuildFAdd(bld->builder, res,
+ LLVMBuildExtractElement(bld->builder,
+ a, index, ""),
+ "");
+ else
+ res = LLVMBuildAdd(bld->builder, res,
+ LLVMBuildExtractElement(bld->builder,
+ a, index, ""),
+ "");
}
return res;
const struct lp_type type = bld->type;
LLVMValueRef res;
+ assert(lp_check_value(type, a));
+ assert(lp_check_value(type, b));
+
if(b == bld->zero)
return a;
if(a == bld->undef || b == bld->undef)
}
if(LLVMIsConstant(a) && LLVMIsConstant(b))
- res = LLVMConstSub(a, b);
+ if (type.floating)
+ res = LLVMConstFSub(a, b);
+ else
+ res = LLVMConstSub(a, b);
else
- res = LLVMBuildSub(bld->builder, a, b, "");
+ if (type.floating)
+ res = LLVMBuildFSub(bld->builder, a, b, "");
+ else
+ res = LLVMBuildSub(bld->builder, a, b, "");
if(bld->type.norm && (bld->type.floating || bld->type.fixed))
res = lp_build_max_simple(bld, res, bld->zero);
LLVMValueRef c8;
LLVMValueRef ab;
+ assert(!i16_type.floating);
+ assert(lp_check_value(i16_type, a));
+ assert(lp_check_value(i16_type, b));
+
c8 = lp_build_const_int_vec(i16_type, 8);
#if 0
LLVMValueRef shift;
LLVMValueRef res;
+ assert(lp_check_value(type, a));
+ assert(lp_check_value(type, b));
+
if(a == bld->zero)
return bld->zero;
if(a == bld->one)
shift = NULL;
if(LLVMIsConstant(a) && LLVMIsConstant(b)) {
- res = LLVMConstMul(a, b);
+ if (type.floating)
+ res = LLVMConstFMul(a, b);
+ else
+ res = LLVMConstMul(a, b);
if(shift) {
if(type.sign)
res = LLVMConstAShr(res, shift);
}
}
else {
- res = LLVMBuildMul(bld->builder, a, b, "");
+ if (type.floating)
+ res = LLVMBuildFMul(bld->builder, a, b, "");
+ else
+ res = LLVMBuildMul(bld->builder, a, b, "");
if(shift) {
if(type.sign)
res = LLVMBuildAShr(bld->builder, res, shift, "");
{
LLVMValueRef factor;
+ assert(lp_check_value(bld->type, a));
+
if(b == 0)
return bld->zero;
return a;
if(b == -1)
- return LLVMBuildNeg(bld->builder, a, "");
+ return lp_build_negate(bld, a);
if(b == 2 && bld->type.floating)
return lp_build_add(bld, a, a);
- if(util_is_pot(b)) {
+ if(util_is_power_of_two(b)) {
unsigned shift = ffs(b) - 1;
if(bld->type.floating) {
{
const struct lp_type type = bld->type;
+ assert(lp_check_value(type, a));
+ assert(lp_check_value(type, b));
+
if(a == bld->zero)
return bld->zero;
if(a == bld->one)
if(a == bld->undef || b == bld->undef)
return bld->undef;
- if(LLVMIsConstant(a) && LLVMIsConstant(b))
- return LLVMConstFDiv(a, b);
+ if(LLVMIsConstant(a) && LLVMIsConstant(b)) {
+ if (type.floating)
+ return LLVMConstFDiv(a, b);
+ else if (type.sign)
+ return LLVMConstSDiv(a, b);
+ else
+ return LLVMConstUDiv(a, b);
+ }
if(util_cpu_caps.has_sse && type.width == 32 && type.length == 4)
return lp_build_mul(bld, a, lp_build_rcp(bld, b));
- return LLVMBuildFDiv(bld->builder, a, b, "");
+ if (type.floating)
+ return LLVMBuildFDiv(bld->builder, a, b, "");
+ else if (type.sign)
+ return LLVMBuildSDiv(bld->builder, a, b, "");
+ else
+ return LLVMBuildUDiv(bld->builder, a, b, "");
}
/**
- * Linear interpolation.
- *
- * This also works for integer values with a few caveats.
+ * Linear interpolation -- without any checks.
*
* @sa http://www.stereopsis.com/doubleblend.html
*/
-LLVMValueRef
-lp_build_lerp(struct lp_build_context *bld,
- LLVMValueRef x,
- LLVMValueRef v0,
- LLVMValueRef v1)
+static INLINE LLVMValueRef
+lp_build_lerp_simple(struct lp_build_context *bld,
+ LLVMValueRef x,
+ LLVMValueRef v0,
+ LLVMValueRef v1)
{
LLVMValueRef delta;
LLVMValueRef res;
+ assert(lp_check_value(bld->type, x));
+ assert(lp_check_value(bld->type, v0));
+ assert(lp_check_value(bld->type, v1));
+
delta = lp_build_sub(bld, v1, v0);
res = lp_build_mul(bld, x, delta);
res = lp_build_add(bld, v0, res);
- if(bld->type.fixed)
+ if (bld->type.fixed) {
/* XXX: This step is necessary for lerping 8bit colors stored on 16bits,
* but it will be wrong for other uses. Basically we need a more
* powerful lp_type, capable of further distinguishing the values
* interpretation from the value storage. */
res = LLVMBuildAnd(bld->builder, res, lp_build_const_int_vec(bld->type, (1 << bld->type.width/2) - 1), "");
+ }
+
+ return res;
+}
+
+
+/**
+ * Linear interpolation.
+ */
+LLVMValueRef
+lp_build_lerp(struct lp_build_context *bld,
+ LLVMValueRef x,
+ LLVMValueRef v0,
+ LLVMValueRef v1)
+{
+ const struct lp_type type = bld->type;
+ LLVMValueRef res;
+
+ assert(lp_check_value(type, x));
+ assert(lp_check_value(type, v0));
+ assert(lp_check_value(type, v1));
+
+ if (type.norm) {
+ struct lp_type wide_type;
+ struct lp_build_context wide_bld;
+ LLVMValueRef xl, xh, v0l, v0h, v1l, v1h, resl, resh;
+ LLVMValueRef shift;
+
+ assert(type.length >= 2);
+ assert(!type.sign);
+
+ /*
+ * Create a wider type, enough to hold the intermediate result of the
+ * multiplication.
+ */
+ memset(&wide_type, 0, sizeof wide_type);
+ wide_type.fixed = TRUE;
+ wide_type.width = type.width*2;
+ wide_type.length = type.length/2;
+
+ lp_build_context_init(&wide_bld, bld->builder, wide_type);
+
+ lp_build_unpack2(bld->builder, type, wide_type, x, &xl, &xh);
+ lp_build_unpack2(bld->builder, type, wide_type, v0, &v0l, &v0h);
+ lp_build_unpack2(bld->builder, type, wide_type, v1, &v1l, &v1h);
+
+ /*
+ * Scale x from [0, 255] to [0, 256]
+ */
+
+ shift = lp_build_const_int_vec(wide_type, type.width - 1);
+
+ xl = lp_build_add(&wide_bld, xl,
+ LLVMBuildAShr(bld->builder, xl, shift, ""));
+ xh = lp_build_add(&wide_bld, xh,
+ LLVMBuildAShr(bld->builder, xh, shift, ""));
+
+ /*
+ * Lerp both halves.
+ */
+
+ resl = lp_build_lerp_simple(&wide_bld, xl, v0l, v1l);
+ resh = lp_build_lerp_simple(&wide_bld, xh, v0h, v1h);
+
+ res = lp_build_pack2(bld->builder, wide_type, type, resl, resh);
+ } else {
+ res = lp_build_lerp_simple(bld, x, v0, v1);
+ }
return res;
}
LLVMValueRef a,
LLVMValueRef b)
{
+ assert(lp_check_value(bld->type, a));
+ assert(lp_check_value(bld->type, b));
+
if(a == bld->undef || b == bld->undef)
return bld->undef;
LLVMValueRef a,
LLVMValueRef b)
{
+ assert(lp_check_value(bld->type, a));
+ assert(lp_check_value(bld->type, b));
+
if(a == bld->undef || b == bld->undef)
return bld->undef;
LLVMValueRef min,
LLVMValueRef max)
{
+ assert(lp_check_value(bld->type, a));
+ assert(lp_check_value(bld->type, min));
+ assert(lp_check_value(bld->type, max));
+
a = lp_build_min(bld, a, max);
a = lp_build_max(bld, a, min);
return a;
const struct lp_type type = bld->type;
LLVMTypeRef vec_type = lp_build_vec_type(type);
+ assert(lp_check_value(type, a));
+
if(!type.sign)
return a;
lp_build_negate(struct lp_build_context *bld,
LLVMValueRef a)
{
- return LLVMBuildNeg(bld->builder, a, "");
+ assert(lp_check_value(bld->type, a));
+
+#if HAVE_LLVM >= 0x0207
+ if (bld->type.floating)
+ a = LLVMBuildFNeg(bld->builder, a, "");
+ else
+#endif
+ a = LLVMBuildNeg(bld->builder, a, "");
+
+ return a;
}
LLVMValueRef cond;
LLVMValueRef res;
+ assert(lp_check_value(type, a));
+
/* Handle non-zero case */
if(!type.sign) {
/* if not zero then sign must be positive */
LLVMValueRef val, res;
assert(type.floating);
+ assert(lp_check_value(type, a));
/* val = reinterpret_cast<int>(a) */
val = LLVMBuildBitCast(bld->builder, a, int_vec_type, "");
enum lp_build_round_sse41_mode mode)
{
const struct lp_type type = bld->type;
- LLVMTypeRef vec_type = lp_build_vec_type(type);
+ LLVMTypeRef i32t = LLVMInt32Type();
const char *intrinsic;
+ LLVMValueRef res;
assert(type.floating);
- assert(type.width*type.length == 128);
+
assert(lp_check_value(type, a));
assert(util_cpu_caps.has_sse4_1);
- switch(type.width) {
- case 32:
- intrinsic = "llvm.x86.sse41.round.ps";
- break;
- case 64:
- intrinsic = "llvm.x86.sse41.round.pd";
- break;
- default:
- assert(0);
- return bld->undef;
+ if (type.length == 1) {
+ LLVMTypeRef vec_type;
+ LLVMValueRef undef;
+ LLVMValueRef args[3];
+ LLVMValueRef index0 = LLVMConstInt(i32t, 0, 0);
+
+ switch(type.width) {
+ case 32:
+ intrinsic = "llvm.x86.sse41.round.ss";
+ break;
+ case 64:
+ intrinsic = "llvm.x86.sse41.round.sd";
+ break;
+ default:
+ assert(0);
+ return bld->undef;
+ }
+
+ vec_type = LLVMVectorType(bld->elem_type, 4);
+
+ undef = LLVMGetUndef(vec_type);
+
+ args[0] = undef;
+ args[1] = LLVMBuildInsertElement(bld->builder, undef, a, index0, "");
+ args[2] = LLVMConstInt(i32t, mode, 0);
+
+ res = lp_build_intrinsic(bld->builder, intrinsic,
+ vec_type, args, Elements(args));
+
+ res = LLVMBuildExtractElement(bld->builder, res, index0, "");
+ }
+ else {
+ assert(type.width*type.length == 128);
+
+ switch(type.width) {
+ case 32:
+ intrinsic = "llvm.x86.sse41.round.ps";
+ break;
+ case 64:
+ intrinsic = "llvm.x86.sse41.round.pd";
+ break;
+ default:
+ assert(0);
+ return bld->undef;
+ }
+
+ res = lp_build_intrinsic_binary(bld->builder, intrinsic,
+ bld->vec_type, a,
+ LLVMConstInt(i32t, mode, 0));
}
- return lp_build_intrinsic_binary(bld->builder, intrinsic, vec_type, a,
- LLVMConstInt(LLVMInt32Type(), mode, 0));
+ return res;
}
+/**
+ * Return the integer part of a float (vector) value. The returned value is
+ * a float (vector).
+ * Ex: trunc(-1.5) = 1.0
+ */
LLVMValueRef
lp_build_trunc(struct lp_build_context *bld,
LLVMValueRef a)
assert(type.floating);
assert(lp_check_value(type, a));
- if (util_cpu_caps.has_sse4_1 && type.width*type.length == 128)
+ if (util_cpu_caps.has_sse4_1 &&
+ (type.length == 1 || type.width*type.length == 128)) {
return lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_TRUNCATE);
+ }
else {
LLVMTypeRef vec_type = lp_build_vec_type(type);
LLVMTypeRef int_vec_type = lp_build_int_vec_type(type);
}
+/**
+ * Return float (vector) rounded to nearest integer (vector). The returned
+ * value is a float (vector).
+ * Ex: round(0.9) = 1.0
+ * Ex: round(-1.5) = -2.0
+ */
LLVMValueRef
lp_build_round(struct lp_build_context *bld,
LLVMValueRef a)
assert(type.floating);
assert(lp_check_value(type, a));
- if (util_cpu_caps.has_sse4_1 && type.width*type.length == 128)
+ if (util_cpu_caps.has_sse4_1 &&
+ (type.length == 1 || type.width*type.length == 128)) {
return lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_NEAREST);
+ }
else {
LLVMTypeRef vec_type = lp_build_vec_type(type);
LLVMValueRef res;
}
+/**
+ * Return floor of float (vector), result is a float (vector)
+ * Ex: floor(1.1) = 1.0
+ * Ex: floor(-1.1) = -2.0
+ */
LLVMValueRef
lp_build_floor(struct lp_build_context *bld,
LLVMValueRef a)
assert(type.floating);
assert(lp_check_value(type, a));
- if (util_cpu_caps.has_sse4_1 && type.width*type.length == 128)
+ if (util_cpu_caps.has_sse4_1 &&
+ (type.length == 1 || type.width*type.length == 128)) {
return lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_FLOOR);
+ }
else {
LLVMTypeRef vec_type = lp_build_vec_type(type);
LLVMValueRef res;
}
+/**
+ * Return ceiling of float (vector), returning float (vector).
+ * Ex: ceil( 1.1) = 2.0
+ * Ex: ceil(-1.1) = -1.0
+ */
LLVMValueRef
lp_build_ceil(struct lp_build_context *bld,
LLVMValueRef a)
assert(type.floating);
assert(lp_check_value(type, a));
- if (util_cpu_caps.has_sse4_1 && type.width*type.length == 128)
+ if (util_cpu_caps.has_sse4_1 &&
+ (type.length == 1 || type.width*type.length == 128)) {
return lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_CEIL);
+ }
else {
LLVMTypeRef vec_type = lp_build_vec_type(type);
LLVMValueRef res;
/**
- * Return fractional part of 'a' computed as a - floor(f)
+ * Return fractional part of 'a' computed as a - floor(a)
* Typically used in texture coord arithmetic.
*/
LLVMValueRef
/**
- * Convert to integer, through whichever rounding method that's fastest,
- * typically truncating toward zero.
+ * Return the integer part of a float (vector) value. The returned value is
+ * an integer (vector).
+ * Ex: itrunc(-1.5) = 1
*/
LLVMValueRef
lp_build_itrunc(struct lp_build_context *bld,
/**
- * Convert float[] to int[] with round().
+ * Return float (vector) rounded to nearest integer (vector). The returned
+ * value is an integer (vector).
+ * Ex: iround(0.9) = 1
+ * Ex: iround(-1.5) = -2
*/
LLVMValueRef
lp_build_iround(struct lp_build_context *bld,
LLVMValueRef a)
{
const struct lp_type type = bld->type;
- LLVMTypeRef int_vec_type = lp_build_int_vec_type(type);
+ LLVMTypeRef int_vec_type = bld->int_vec_type;
LLVMValueRef res;
assert(type.floating);
assert(lp_check_value(type, a));
- if (util_cpu_caps.has_sse4_1 && type.width*type.length == 128) {
+ if (util_cpu_caps.has_sse4_1 &&
+ (type.length == 1 || type.width*type.length == 128)) {
res = lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_NEAREST);
}
else {
- LLVMTypeRef vec_type = lp_build_vec_type(type);
- LLVMValueRef mask = lp_build_const_int_vec(type, (unsigned long long)1 << (type.width - 1));
- LLVMValueRef sign;
LLVMValueRef half;
- /* get sign bit */
- sign = LLVMBuildBitCast(bld->builder, a, int_vec_type, "");
- sign = LLVMBuildAnd(bld->builder, sign, mask, "");
-
- /* sign * 0.5 */
half = lp_build_const_vec(type, 0.5);
- half = LLVMBuildBitCast(bld->builder, half, int_vec_type, "");
- half = LLVMBuildOr(bld->builder, sign, half, "");
- half = LLVMBuildBitCast(bld->builder, half, vec_type, "");
- res = LLVMBuildAdd(bld->builder, a, half, "");
+ if (type.sign) {
+ LLVMTypeRef vec_type = bld->vec_type;
+ LLVMValueRef mask = lp_build_const_int_vec(type, (unsigned long long)1 << (type.width - 1));
+ LLVMValueRef sign;
+
+ /* get sign bit */
+ sign = LLVMBuildBitCast(bld->builder, a, int_vec_type, "");
+ sign = LLVMBuildAnd(bld->builder, sign, mask, "");
+
+ /* sign * 0.5 */
+ half = LLVMBuildBitCast(bld->builder, half, int_vec_type, "");
+ half = LLVMBuildOr(bld->builder, sign, half, "");
+ half = LLVMBuildBitCast(bld->builder, half, vec_type, "");
+ }
+
+ res = LLVMBuildFAdd(bld->builder, a, half, "");
}
res = LLVMBuildFPToSI(bld->builder, res, int_vec_type, "");
/**
- * Convert float[] to int[] with floor().
+ * Return floor of float (vector), result is an int (vector)
+ * Ex: ifloor(1.1) = 1.0
+ * Ex: ifloor(-1.1) = -2.0
*/
LLVMValueRef
lp_build_ifloor(struct lp_build_context *bld,
LLVMValueRef a)
{
const struct lp_type type = bld->type;
- LLVMTypeRef int_vec_type = lp_build_int_vec_type(type);
+ LLVMTypeRef int_vec_type = bld->int_vec_type;
LLVMValueRef res;
assert(type.floating);
assert(lp_check_value(type, a));
- if (util_cpu_caps.has_sse4_1 && type.width*type.length == 128) {
+ if (util_cpu_caps.has_sse4_1 &&
+ (type.length == 1 || type.width*type.length == 128)) {
res = lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_FLOOR);
}
else {
- /* Take the sign bit and add it to 1 constant */
- LLVMTypeRef vec_type = lp_build_vec_type(type);
- unsigned mantissa = lp_mantissa(type);
- LLVMValueRef mask = lp_build_const_int_vec(type, (unsigned long long)1 << (type.width - 1));
- LLVMValueRef sign;
- LLVMValueRef offset;
-
- /* sign = a < 0 ? ~0 : 0 */
- sign = LLVMBuildBitCast(bld->builder, a, int_vec_type, "");
- sign = LLVMBuildAnd(bld->builder, sign, mask, "");
- sign = LLVMBuildAShr(bld->builder, sign, lp_build_const_int_vec(type, type.width - 1), "");
- lp_build_name(sign, "floor.sign");
-
- /* offset = -0.99999(9)f */
- offset = lp_build_const_vec(type, -(double)(((unsigned long long)1 << mantissa) - 1)/((unsigned long long)1 << mantissa));
- offset = LLVMConstBitCast(offset, int_vec_type);
-
- /* offset = a < 0 ? -0.99999(9)f : 0.0f */
- offset = LLVMBuildAnd(bld->builder, offset, sign, "");
- offset = LLVMBuildBitCast(bld->builder, offset, vec_type, "");
- lp_build_name(offset, "floor.offset");
-
- res = LLVMBuildAdd(bld->builder, a, offset, "");
- lp_build_name(res, "floor.res");
+ res = a;
+
+ if (type.sign) {
+ /* Take the sign bit and add it to 1 constant */
+ LLVMTypeRef vec_type = bld->vec_type;
+ unsigned mantissa = lp_mantissa(type);
+ LLVMValueRef mask = lp_build_const_int_vec(type, (unsigned long long)1 << (type.width - 1));
+ LLVMValueRef sign;
+ LLVMValueRef offset;
+
+ /* sign = a < 0 ? ~0 : 0 */
+ sign = LLVMBuildBitCast(bld->builder, a, int_vec_type, "");
+ sign = LLVMBuildAnd(bld->builder, sign, mask, "");
+ sign = LLVMBuildAShr(bld->builder, sign, lp_build_const_int_vec(type, type.width - 1), "ifloor.sign");
+
+ /* offset = -0.99999(9)f */
+ offset = lp_build_const_vec(type, -(double)(((unsigned long long)1 << mantissa) - 10)/((unsigned long long)1 << mantissa));
+ offset = LLVMConstBitCast(offset, int_vec_type);
+
+ /* offset = a < 0 ? offset : 0.0f */
+ offset = LLVMBuildAnd(bld->builder, offset, sign, "");
+ offset = LLVMBuildBitCast(bld->builder, offset, vec_type, "ifloor.offset");
+
+ res = LLVMBuildFAdd(bld->builder, res, offset, "ifloor.res");
+ }
}
- res = LLVMBuildFPToSI(bld->builder, res, int_vec_type, "");
- lp_build_name(res, "floor");
+ /* round to nearest (toward zero) */
+ res = LLVMBuildFPToSI(bld->builder, res, int_vec_type, "ifloor.res");
return res;
}
+/**
+ * Return ceiling of float (vector), returning int (vector).
+ * Ex: iceil( 1.1) = 2
+ * Ex: iceil(-1.1) = -1
+ */
LLVMValueRef
lp_build_iceil(struct lp_build_context *bld,
LLVMValueRef a)
{
const struct lp_type type = bld->type;
- LLVMTypeRef int_vec_type = lp_build_int_vec_type(type);
+ LLVMTypeRef int_vec_type = bld->int_vec_type;
LLVMValueRef res;
assert(type.floating);
assert(lp_check_value(type, a));
- if (util_cpu_caps.has_sse4_1 && type.width*type.length == 128) {
+ if (util_cpu_caps.has_sse4_1 &&
+ (type.length == 1 || type.width*type.length == 128)) {
res = lp_build_round_sse41(bld, a, LP_BUILD_ROUND_SSE41_CEIL);
}
else {
- /* TODO: mimic lp_build_ifloor() here */
- assert(0);
- res = bld->undef;
+ LLVMTypeRef vec_type = bld->vec_type;
+ unsigned mantissa = lp_mantissa(type);
+ LLVMValueRef offset;
+
+ /* offset = 0.99999(9)f */
+ offset = lp_build_const_vec(type, (double)(((unsigned long long)1 << mantissa) - 10)/((unsigned long long)1 << mantissa));
+
+ if (type.sign) {
+ LLVMValueRef mask = lp_build_const_int_vec(type, (unsigned long long)1 << (type.width - 1));
+ LLVMValueRef sign;
+
+ /* sign = a < 0 ? 0 : ~0 */
+ sign = LLVMBuildBitCast(bld->builder, a, int_vec_type, "");
+ sign = LLVMBuildAnd(bld->builder, sign, mask, "");
+ sign = LLVMBuildAShr(bld->builder, sign, lp_build_const_int_vec(type, type.width - 1), "iceil.sign");
+ sign = LLVMBuildNot(bld->builder, sign, "iceil.not");
+
+ /* offset = a < 0 ? 0.0 : offset */
+ offset = LLVMConstBitCast(offset, int_vec_type);
+ offset = LLVMBuildAnd(bld->builder, offset, sign, "");
+ offset = LLVMBuildBitCast(bld->builder, offset, vec_type, "iceil.offset");
+ }
+
+ res = LLVMBuildFAdd(bld->builder, a, offset, "iceil.res");
}
- res = LLVMBuildFPToSI(bld->builder, res, int_vec_type, "");
+ /* round to nearest (toward zero) */
+ res = LLVMBuildFPToSI(bld->builder, res, int_vec_type, "iceil.res");
return res;
}
LLVMTypeRef vec_type = lp_build_vec_type(type);
char intrinsic[32];
+ assert(lp_check_value(type, a));
+
/* TODO: optimize the constant case */
/* TODO: optimize the constant case */
}
+/**
+ * Do one Newton-Raphson step to improve reciprocate precision:
+ *
+ * x_{i+1} = x_i * (2 - a * x_i)
+ *
+ * XXX: Unfortunately this won't give IEEE-754 conformant results for 0 or
+ * +/-Inf, giving NaN instead. Certain applications rely on this behavior,
+ * such as Google Earth, which does RCP(RSQRT(0.0) when drawing the Earth's
+ * halo. It would be necessary to clamp the argument to prevent this.
+ *
+ * See also:
+ * - http://en.wikipedia.org/wiki/Division_(digital)#Newton.E2.80.93Raphson_division
+ * - http://softwarecommunity.intel.com/articles/eng/1818.htm
+ */
+static INLINE LLVMValueRef
+lp_build_rcp_refine(struct lp_build_context *bld,
+ LLVMValueRef a,
+ LLVMValueRef rcp_a)
+{
+ LLVMValueRef two = lp_build_const_vec(bld->type, 2.0);
+ LLVMValueRef res;
+
+ res = LLVMBuildFMul(bld->builder, a, rcp_a, "");
+ res = LLVMBuildFSub(bld->builder, two, res, "");
+ res = LLVMBuildFMul(bld->builder, rcp_a, res, "");
+
+ return res;
+}
+
+
LLVMValueRef
lp_build_rcp(struct lp_build_context *bld,
LLVMValueRef a)
{
const struct lp_type type = bld->type;
+ assert(lp_check_value(type, a));
+
if(a == bld->zero)
return bld->undef;
if(a == bld->one)
if(LLVMIsConstant(a))
return LLVMConstFDiv(bld->one, a);
- if(util_cpu_caps.has_sse && type.width == 32 && type.length == 4) {
- /*
- * XXX: Added precision is not always necessary, so only enable this
- * when we have a better system in place to track minimum precision.
- */
-
-#if 0
- /*
- * Do one Newton-Raphson step to improve precision:
- *
- * x1 = (2 - a * rcp(a)) * rcp(a)
- */
+ /*
+ * We don't use RCPPS because:
+ * - it only has 10bits of precision
+ * - it doesn't even get the reciprocate of 1.0 exactly
+ * - doing Newton-Rapshon steps yields wrong (NaN) values for 0.0 or Inf
+ * - for recent processors the benefit over DIVPS is marginal, a case
+ * depedent
+ *
+ * We could still use it on certain processors if benchmarks show that the
+ * RCPPS plus necessary workarounds are still preferrable to DIVPS; or for
+ * particular uses that require less workarounds.
+ */
- LLVMValueRef two = lp_build_const_vec(bld->type, 2.0);
- LLVMValueRef rcp_a;
+ if (FALSE && util_cpu_caps.has_sse && type.width == 32 && type.length == 4) {
+ const unsigned num_iterations = 0;
LLVMValueRef res;
+ unsigned i;
- rcp_a = lp_build_intrinsic_unary(bld->builder, "llvm.x86.sse.rcp.ps", lp_build_vec_type(type), a);
+ res = lp_build_intrinsic_unary(bld->builder, "llvm.x86.sse.rcp.ps", bld->vec_type, a);
- res = LLVMBuildMul(bld->builder, a, rcp_a, "");
- res = LLVMBuildSub(bld->builder, two, res, "");
- res = LLVMBuildMul(bld->builder, res, rcp_a, "");
+ for (i = 0; i < num_iterations; ++i) {
+ res = lp_build_rcp_refine(bld, a, res);
+ }
- return rcp_a;
-#else
- return lp_build_intrinsic_unary(bld->builder, "llvm.x86.sse.rcp.ps", lp_build_vec_type(type), a);
-#endif
+ return res;
}
return LLVMBuildFDiv(bld->builder, bld->one, a, "");
}
+/**
+ * Do one Newton-Raphson step to improve rsqrt precision:
+ *
+ * x_{i+1} = 0.5 * x_i * (3.0 - a * x_i * x_i)
+ *
+ * See also:
+ * - http://softwarecommunity.intel.com/articles/eng/1818.htm
+ */
+static INLINE LLVMValueRef
+lp_build_rsqrt_refine(struct lp_build_context *bld,
+ LLVMValueRef a,
+ LLVMValueRef rsqrt_a)
+{
+ LLVMValueRef half = lp_build_const_vec(bld->type, 0.5);
+ LLVMValueRef three = lp_build_const_vec(bld->type, 3.0);
+ LLVMValueRef res;
+
+ res = LLVMBuildFMul(bld->builder, rsqrt_a, rsqrt_a, "");
+ res = LLVMBuildFMul(bld->builder, a, res, "");
+ res = LLVMBuildFSub(bld->builder, three, res, "");
+ res = LLVMBuildFMul(bld->builder, rsqrt_a, res, "");
+ res = LLVMBuildFMul(bld->builder, half, res, "");
+
+ return res;
+}
+
+
/**
* Generate 1/sqrt(a)
*/
{
const struct lp_type type = bld->type;
+ assert(lp_check_value(type, a));
+
assert(type.floating);
- if(util_cpu_caps.has_sse && type.width == 32 && type.length == 4)
- return lp_build_intrinsic_unary(bld->builder, "llvm.x86.sse.rsqrt.ps", lp_build_vec_type(type), a);
+ if (util_cpu_caps.has_sse && type.width == 32 && type.length == 4) {
+ const unsigned num_iterations = 0;
+ LLVMValueRef res;
+ unsigned i;
+
+ res = lp_build_intrinsic_unary(bld->builder, "llvm.x86.sse.rsqrt.ps", bld->vec_type, a);
+
+ for (i = 0; i < num_iterations; ++i) {
+ res = lp_build_rsqrt_refine(bld, a, res);
+ }
+
+ return res;
+ }
return lp_build_rcp(bld, lp_build_sqrt(bld, a));
}
*/
LLVMValueRef FOPi = lp_build_const_v4sf(1.27323954473516);
- LLVMValueRef scale_y = LLVMBuildMul(b, x_abs, FOPi, "scale_y");
+ LLVMValueRef scale_y = LLVMBuildFMul(b, x_abs, FOPi, "scale_y");
/*
* store the integer part of y in mm0
* xmm2 = _mm_mul_ps(y, xmm2);
* xmm3 = _mm_mul_ps(y, xmm3);
*/
- LLVMValueRef xmm1 = LLVMBuildMul(b, y_2, DP1, "xmm1");
- LLVMValueRef xmm2 = LLVMBuildMul(b, y_2, DP2, "xmm2");
- LLVMValueRef xmm3 = LLVMBuildMul(b, y_2, DP3, "xmm3");
+ LLVMValueRef xmm1 = LLVMBuildFMul(b, y_2, DP1, "xmm1");
+ LLVMValueRef xmm2 = LLVMBuildFMul(b, y_2, DP2, "xmm2");
+ LLVMValueRef xmm3 = LLVMBuildFMul(b, y_2, DP3, "xmm3");
/*
* x = _mm_add_ps(x, xmm1);
* x = _mm_add_ps(x, xmm3);
*/
- LLVMValueRef x_1 = LLVMBuildAdd(b, x_abs, xmm1, "x_1");
- LLVMValueRef x_2 = LLVMBuildAdd(b, x_1, xmm2, "x_2");
- LLVMValueRef x_3 = LLVMBuildAdd(b, x_2, xmm3, "x_3");
+ LLVMValueRef x_1 = LLVMBuildFAdd(b, x_abs, xmm1, "x_1");
+ LLVMValueRef x_2 = LLVMBuildFAdd(b, x_1, xmm2, "x_2");
+ LLVMValueRef x_3 = LLVMBuildFAdd(b, x_2, xmm3, "x_3");
/*
* Evaluate the first polynom (0 <= x <= Pi/4)
*
* z = _mm_mul_ps(x,x);
*/
- LLVMValueRef z = LLVMBuildMul(b, x_3, x_3, "z");
+ LLVMValueRef z = LLVMBuildFMul(b, x_3, x_3, "z");
/*
* _PS_CONST(coscof_p0, 2.443315711809948E-005);
* y = *(v4sf*)_ps_coscof_p0;
* y = _mm_mul_ps(y, z);
*/
- LLVMValueRef y_3 = LLVMBuildMul(b, z, coscof_p0, "y_3");
- LLVMValueRef y_4 = LLVMBuildAdd(b, y_3, coscof_p1, "y_4");
- LLVMValueRef y_5 = LLVMBuildMul(b, y_4, z, "y_5");
- LLVMValueRef y_6 = LLVMBuildAdd(b, y_5, coscof_p2, "y_6");
- LLVMValueRef y_7 = LLVMBuildMul(b, y_6, z, "y_7");
- LLVMValueRef y_8 = LLVMBuildMul(b, y_7, z, "y_8");
+ LLVMValueRef y_3 = LLVMBuildFMul(b, z, coscof_p0, "y_3");
+ LLVMValueRef y_4 = LLVMBuildFAdd(b, y_3, coscof_p1, "y_4");
+ LLVMValueRef y_5 = LLVMBuildFMul(b, y_4, z, "y_5");
+ LLVMValueRef y_6 = LLVMBuildFAdd(b, y_5, coscof_p2, "y_6");
+ LLVMValueRef y_7 = LLVMBuildFMul(b, y_6, z, "y_7");
+ LLVMValueRef y_8 = LLVMBuildFMul(b, y_7, z, "y_8");
/*
* y = _mm_add_ps(y, *(v4sf*)_ps_1);
*/
LLVMValueRef half = lp_build_const_v4sf(0.5);
- LLVMValueRef tmp = LLVMBuildMul(b, z, half, "tmp");
- LLVMValueRef y_9 = LLVMBuildSub(b, y_8, tmp, "y_8");
+ LLVMValueRef tmp = LLVMBuildFMul(b, z, half, "tmp");
+ LLVMValueRef y_9 = LLVMBuildFSub(b, y_8, tmp, "y_8");
LLVMValueRef one = lp_build_const_v4sf(1.0);
- LLVMValueRef y_10 = LLVMBuildAdd(b, y_9, one, "y_9");
+ LLVMValueRef y_10 = LLVMBuildFAdd(b, y_9, one, "y_9");
/*
* _PS_CONST(sincof_p0, -1.9515295891E-4);
* y2 = _mm_add_ps(y2, x);
*/
- LLVMValueRef y2_3 = LLVMBuildMul(b, z, sincof_p0, "y2_3");
- LLVMValueRef y2_4 = LLVMBuildAdd(b, y2_3, sincof_p1, "y2_4");
- LLVMValueRef y2_5 = LLVMBuildMul(b, y2_4, z, "y2_5");
- LLVMValueRef y2_6 = LLVMBuildAdd(b, y2_5, sincof_p2, "y2_6");
- LLVMValueRef y2_7 = LLVMBuildMul(b, y2_6, z, "y2_7");
- LLVMValueRef y2_8 = LLVMBuildMul(b, y2_7, x_3, "y2_8");
- LLVMValueRef y2_9 = LLVMBuildAdd(b, y2_8, x_3, "y2_9");
+ LLVMValueRef y2_3 = LLVMBuildFMul(b, z, sincof_p0, "y2_3");
+ LLVMValueRef y2_4 = LLVMBuildFAdd(b, y2_3, sincof_p1, "y2_4");
+ LLVMValueRef y2_5 = LLVMBuildFMul(b, y2_4, z, "y2_5");
+ LLVMValueRef y2_6 = LLVMBuildFAdd(b, y2_5, sincof_p2, "y2_6");
+ LLVMValueRef y2_7 = LLVMBuildFMul(b, y2_6, z, "y2_7");
+ LLVMValueRef y2_8 = LLVMBuildFMul(b, y2_7, x_3, "y2_8");
+ LLVMValueRef y2_9 = LLVMBuildFAdd(b, y2_8, x_3, "y2_9");
/*
* select the correct result from the two polynoms
*/
LLVMValueRef FOPi = lp_build_const_v4sf(1.27323954473516);
- LLVMValueRef scale_y = LLVMBuildMul(b, x_abs, FOPi, "scale_y");
+ LLVMValueRef scale_y = LLVMBuildFMul(b, x_abs, FOPi, "scale_y");
/*
* store the integer part of y in mm0
* xmm2 = _mm_mul_ps(y, xmm2);
* xmm3 = _mm_mul_ps(y, xmm3);
*/
- LLVMValueRef xmm1 = LLVMBuildMul(b, y_2, DP1, "xmm1");
- LLVMValueRef xmm2 = LLVMBuildMul(b, y_2, DP2, "xmm2");
- LLVMValueRef xmm3 = LLVMBuildMul(b, y_2, DP3, "xmm3");
+ LLVMValueRef xmm1 = LLVMBuildFMul(b, y_2, DP1, "xmm1");
+ LLVMValueRef xmm2 = LLVMBuildFMul(b, y_2, DP2, "xmm2");
+ LLVMValueRef xmm3 = LLVMBuildFMul(b, y_2, DP3, "xmm3");
/*
* x = _mm_add_ps(x, xmm1);
* x = _mm_add_ps(x, xmm3);
*/
- LLVMValueRef x_1 = LLVMBuildAdd(b, x_abs, xmm1, "x_1");
- LLVMValueRef x_2 = LLVMBuildAdd(b, x_1, xmm2, "x_2");
- LLVMValueRef x_3 = LLVMBuildAdd(b, x_2, xmm3, "x_3");
+ LLVMValueRef x_1 = LLVMBuildFAdd(b, x_abs, xmm1, "x_1");
+ LLVMValueRef x_2 = LLVMBuildFAdd(b, x_1, xmm2, "x_2");
+ LLVMValueRef x_3 = LLVMBuildFAdd(b, x_2, xmm3, "x_3");
/*
* Evaluate the first polynom (0 <= x <= Pi/4)
*
* z = _mm_mul_ps(x,x);
*/
- LLVMValueRef z = LLVMBuildMul(b, x_3, x_3, "z");
+ LLVMValueRef z = LLVMBuildFMul(b, x_3, x_3, "z");
/*
* _PS_CONST(coscof_p0, 2.443315711809948E-005);
* y = *(v4sf*)_ps_coscof_p0;
* y = _mm_mul_ps(y, z);
*/
- LLVMValueRef y_3 = LLVMBuildMul(b, z, coscof_p0, "y_3");
- LLVMValueRef y_4 = LLVMBuildAdd(b, y_3, coscof_p1, "y_4");
- LLVMValueRef y_5 = LLVMBuildMul(b, y_4, z, "y_5");
- LLVMValueRef y_6 = LLVMBuildAdd(b, y_5, coscof_p2, "y_6");
- LLVMValueRef y_7 = LLVMBuildMul(b, y_6, z, "y_7");
- LLVMValueRef y_8 = LLVMBuildMul(b, y_7, z, "y_8");
+ LLVMValueRef y_3 = LLVMBuildFMul(b, z, coscof_p0, "y_3");
+ LLVMValueRef y_4 = LLVMBuildFAdd(b, y_3, coscof_p1, "y_4");
+ LLVMValueRef y_5 = LLVMBuildFMul(b, y_4, z, "y_5");
+ LLVMValueRef y_6 = LLVMBuildFAdd(b, y_5, coscof_p2, "y_6");
+ LLVMValueRef y_7 = LLVMBuildFMul(b, y_6, z, "y_7");
+ LLVMValueRef y_8 = LLVMBuildFMul(b, y_7, z, "y_8");
/*
* y = _mm_add_ps(y, *(v4sf*)_ps_1);
*/
LLVMValueRef half = lp_build_const_v4sf(0.5);
- LLVMValueRef tmp = LLVMBuildMul(b, z, half, "tmp");
- LLVMValueRef y_9 = LLVMBuildSub(b, y_8, tmp, "y_8");
+ LLVMValueRef tmp = LLVMBuildFMul(b, z, half, "tmp");
+ LLVMValueRef y_9 = LLVMBuildFSub(b, y_8, tmp, "y_8");
LLVMValueRef one = lp_build_const_v4sf(1.0);
- LLVMValueRef y_10 = LLVMBuildAdd(b, y_9, one, "y_9");
+ LLVMValueRef y_10 = LLVMBuildFAdd(b, y_9, one, "y_9");
/*
* _PS_CONST(sincof_p0, -1.9515295891E-4);
* y2 = _mm_add_ps(y2, x);
*/
- LLVMValueRef y2_3 = LLVMBuildMul(b, z, sincof_p0, "y2_3");
- LLVMValueRef y2_4 = LLVMBuildAdd(b, y2_3, sincof_p1, "y2_4");
- LLVMValueRef y2_5 = LLVMBuildMul(b, y2_4, z, "y2_5");
- LLVMValueRef y2_6 = LLVMBuildAdd(b, y2_5, sincof_p2, "y2_6");
- LLVMValueRef y2_7 = LLVMBuildMul(b, y2_6, z, "y2_7");
- LLVMValueRef y2_8 = LLVMBuildMul(b, y2_7, x_3, "y2_8");
- LLVMValueRef y2_9 = LLVMBuildAdd(b, y2_8, x_3, "y2_9");
+ LLVMValueRef y2_3 = LLVMBuildFMul(b, z, sincof_p0, "y2_3");
+ LLVMValueRef y2_4 = LLVMBuildFAdd(b, y2_3, sincof_p1, "y2_4");
+ LLVMValueRef y2_5 = LLVMBuildFMul(b, y2_4, z, "y2_5");
+ LLVMValueRef y2_6 = LLVMBuildFAdd(b, y2_5, sincof_p2, "y2_6");
+ LLVMValueRef y2_7 = LLVMBuildFMul(b, y2_6, z, "y2_7");
+ LLVMValueRef y2_8 = LLVMBuildFMul(b, y2_7, x_3, "y2_8");
+ LLVMValueRef y2_9 = LLVMBuildFAdd(b, y2_8, x_3, "y2_9");
/*
* select the correct result from the two polynoms
LLVMValueRef y)
{
/* TODO: optimize the constant case */
- if(LLVMIsConstant(x) && LLVMIsConstant(y))
+ if (gallivm_debug & GALLIVM_DEBUG_PERF &&
+ LLVMIsConstant(x) && LLVMIsConstant(y)) {
debug_printf("%s: inefficient/imprecise constant arithmetic\n",
__FUNCTION__);
+ }
return lp_build_exp2(bld, lp_build_mul(bld, lp_build_log2(bld, x), y));
}
/* log2(e) = 1/log(2) */
LLVMValueRef log2e = lp_build_const_vec(bld->type, 1.4426950408889634);
+ assert(lp_check_value(bld->type, x));
+
return lp_build_mul(bld, log2e, lp_build_exp2(bld, x));
}
/* log(2) */
LLVMValueRef log2 = lp_build_const_vec(bld->type, 0.69314718055994529);
+ assert(lp_check_value(bld->type, x));
+
return lp_build_mul(bld, log2, lp_build_exp2(bld, x));
}
-#define EXP_POLY_DEGREE 3
-#define LOG_POLY_DEGREE 5
-
-
/**
* Generate polynomial.
* Ex: coeffs[0] + x * coeffs[1] + x^2 * coeffs[2].
LLVMValueRef res = NULL;
unsigned i;
+ assert(lp_check_value(bld->type, x));
+
/* TODO: optimize the constant case */
- if(LLVMIsConstant(x))
+ if (gallivm_debug & GALLIVM_DEBUG_PERF &&
+ LLVMIsConstant(x)) {
debug_printf("%s: inefficient/imprecise constant arithmetic\n",
__FUNCTION__);
+ }
for (i = num_coeffs; i--; ) {
LLVMValueRef coeff;
LLVMValueRef expfpart = NULL;
LLVMValueRef res = NULL;
+ assert(lp_check_value(bld->type, x));
+
if(p_exp2_int_part || p_frac_part || p_exp2) {
/* TODO: optimize the constant case */
- if(LLVMIsConstant(x))
+ if (gallivm_debug & GALLIVM_DEBUG_PERF &&
+ LLVMIsConstant(x)) {
debug_printf("%s: inefficient/imprecise constant arithmetic\n",
__FUNCTION__);
+ }
assert(type.floating && type.width == 32);
ipart = lp_build_floor(bld, x);
/* fpart = x - ipart */
- fpart = LLVMBuildSub(bld->builder, x, ipart, "");
+ fpart = LLVMBuildFSub(bld->builder, x, ipart, "");
}
if(p_exp2_int_part || p_exp2) {
expfpart = lp_build_polynomial(bld, fpart, lp_build_exp2_polynomial,
Elements(lp_build_exp2_polynomial));
- res = LLVMBuildMul(bld->builder, expipart, expfpart, "");
+ res = LLVMBuildFMul(bld->builder, expipart, expfpart, "");
}
if(p_exp2_int_part)
LLVMValueRef logmant = NULL;
LLVMValueRef res = NULL;
+ assert(lp_check_value(bld->type, x));
+
if(p_exp || p_floor_log2 || p_log2) {
/* TODO: optimize the constant case */
- if(LLVMIsConstant(x))
+ if (gallivm_debug & GALLIVM_DEBUG_PERF &&
+ LLVMIsConstant(x)) {
debug_printf("%s: inefficient/imprecise constant arithmetic\n",
__FUNCTION__);
+ }
assert(type.floating && type.width == 32);
Elements(lp_build_log2_polynomial));
/* This effectively increases the polynomial degree by one, but ensures that log2(1) == 0*/
- logmant = LLVMBuildMul(bld->builder, logmant, LLVMBuildSub(bld->builder, mant, bld->one, ""), "");
+ logmant = LLVMBuildFMul(bld->builder, logmant, LLVMBuildFSub(bld->builder, mant, bld->one, ""), "");
- res = LLVMBuildAdd(bld->builder, logmant, logexp, "");
+ res = LLVMBuildFAdd(bld->builder, logmant, logexp, "");
}
if(p_exp) {
lp_build_log2_approx(bld, x, NULL, NULL, &res);
return res;
}
+
+
+/**
+ * Faster (and less accurate) log2.
+ *
+ * log2(x) = floor(log2(x)) + frac(x)
+ *
+ * See http://www.flipcode.com/archives/Fast_log_Function.shtml
+ */
+LLVMValueRef
+lp_build_fast_log2(struct lp_build_context *bld,
+ LLVMValueRef x)
+{
+ const struct lp_type type = bld->type;
+ LLVMTypeRef vec_type = bld->vec_type;
+ LLVMTypeRef int_vec_type = bld->int_vec_type;
+
+ unsigned mantissa = lp_mantissa(type);
+ LLVMValueRef mantmask = lp_build_const_int_vec(type, (1ULL << mantissa) - 1);
+ LLVMValueRef one = LLVMConstBitCast(bld->one, int_vec_type);
+
+ LLVMValueRef ipart;
+ LLVMValueRef fpart;
+
+ assert(lp_check_value(bld->type, x));
+
+ assert(type.floating);
+
+ x = LLVMBuildBitCast(bld->builder, x, int_vec_type, "");
+
+ /* ipart = floor(log2(x)) - 1 */
+ ipart = LLVMBuildLShr(bld->builder, x, lp_build_const_int_vec(type, mantissa), "");
+ ipart = LLVMBuildAnd(bld->builder, ipart, lp_build_const_int_vec(type, 255), "");
+ ipart = LLVMBuildSub(bld->builder, ipart, lp_build_const_int_vec(type, 128), "");
+ ipart = LLVMBuildSIToFP(bld->builder, ipart, vec_type, "");
+
+ /* fpart = 1.0 + frac(x) */
+ fpart = LLVMBuildAnd(bld->builder, x, mantmask, "");
+ fpart = LLVMBuildOr(bld->builder, fpart, one, "");
+ fpart = LLVMBuildBitCast(bld->builder, fpart, vec_type, "");
+
+ /* floor(log2(x)) + frac(x) */
+ return LLVMBuildFAdd(bld->builder, ipart, fpart, "");
+}
projects / mesa.git / blobdiff