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llvmpipe: Remove the special path for TGSI_OPCODE_EXP.

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It was wrong for EXP.y, as we clamped the source before computing the
fractional part, and this opcode should be rarely used, so it's not
worth the hassle.
This commit is contained in:
José Fonseca
2013-09-11 12:04:29 +01:00
parent e75211df0f
commit 315f8f17d0
3 changed files with 34 additions and 76 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/gallium/auxiliary/gallivm/lp_bld_arit.c
+34 -54
View File
@@ -3001,12 +3001,9 @@ const double lp_build_exp2_polynomial[] = {
};
void
lp_build_exp2_approx(struct lp_build_context *bld,
LLVMValueRef x,
LLVMValueRef *p_exp2_int_part,
LLVMValueRef *p_frac_part,
LLVMValueRef *p_exp2)
LLVMValueRef
lp_build_exp2(struct lp_build_context *bld,
LLVMValueRef x)
{
LLVMBuilderRef builder = bld->gallivm->builder;
const struct lp_type type = bld->type;
@@ -3019,65 +3016,48 @@ lp_build_exp2_approx(struct lp_build_context *bld,
assert(lp_check_value(bld->type, x));
if(p_exp2_int_part || p_frac_part || p_exp2) {
/* TODO: optimize the constant case */
if (gallivm_debug & GALLIVM_DEBUG_PERF &&
LLVMIsConstant(x)) {
debug_printf("%s: inefficient/imprecise constant arithmetic\n",
__FUNCTION__);
}
assert(type.floating && type.width == 32);
/* We want to preserve NaN and make sure than for exp2 if x > 128,
* the result is INF and if it's smaller than -126.9 the result is 0 */
x = lp_build_min_ext(bld, lp_build_const_vec(bld->gallivm, type, 128.0), x,
GALLIVM_NAN_RETURN_SECOND);
x = lp_build_max_ext(bld, lp_build_const_vec(bld->gallivm, type, -126.99999), x,
GALLIVM_NAN_RETURN_SECOND);
/* ipart = floor(x) */
/* fpart = x - ipart */
lp_build_ifloor_fract(bld, x, &ipart, &fpart);
/* TODO: optimize the constant case */
if (gallivm_debug & GALLIVM_DEBUG_PERF &&
LLVMIsConstant(x)) {
debug_printf("%s: inefficient/imprecise constant arithmetic\n",
__FUNCTION__);
}
if(p_exp2_int_part || p_exp2) {
/* expipart = (float) (1 << ipart) */
expipart = LLVMBuildAdd(builder, ipart,
lp_build_const_int_vec(bld->gallivm, type, 127), "");
expipart = LLVMBuildShl(builder, expipart,
lp_build_const_int_vec(bld->gallivm, type, 23), "");
expipart = LLVMBuildBitCast(builder, expipart, vec_type, "");
}
assert(type.floating && type.width == 32);
if(p_exp2) {
expfpart = lp_build_polynomial(bld, fpart, lp_build_exp2_polynomial,
Elements(lp_build_exp2_polynomial));
/* We want to preserve NaN and make sure than for exp2 if x > 128,
* the result is INF and if it's smaller than -126.9 the result is 0 */
x = lp_build_min_ext(bld, lp_build_const_vec(bld->gallivm, type, 128.0), x,
GALLIVM_NAN_RETURN_SECOND);
x = lp_build_max_ext(bld, lp_build_const_vec(bld->gallivm, type, -126.99999), x,
GALLIVM_NAN_RETURN_SECOND);
res = LLVMBuildFMul(builder, expipart, expfpart, "");
}
if(p_exp2_int_part)
*p_exp2_int_part = expipart;
if(p_frac_part)
*p_frac_part = fpart;
if(p_exp2)
*p_exp2 = res;
}
/* ipart = floor(x) */
/* fpart = x - ipart */
lp_build_ifloor_fract(bld, x, &ipart, &fpart);
/* expipart = (float) (1 << ipart) */
expipart = LLVMBuildAdd(builder, ipart,
lp_build_const_int_vec(bld->gallivm, type, 127), "");
expipart = LLVMBuildShl(builder, expipart,
lp_build_const_int_vec(bld->gallivm, type, 23), "");
expipart = LLVMBuildBitCast(builder, expipart, vec_type, "");
expfpart = lp_build_polynomial(bld, fpart, lp_build_exp2_polynomial,
Elements(lp_build_exp2_polynomial));
res = LLVMBuildFMul(builder, expipart, expfpart, "");
LLVMValueRef
lp_build_exp2(struct lp_build_context *bld,
LLVMValueRef x)
{
LLVMValueRef res;
lp_build_exp2_approx(bld, x, NULL, NULL, &res);
return res;
}
/**
* Extract the exponent of a IEEE-754 floating point value.
*
src/gallium/auxiliary/gallivm/lp_bld_arit.h
-7
View File
@@ -325,13 +325,6 @@ LLVMValueRef
lp_build_ilog2(struct lp_build_context *bld,
LLVMValueRef x);
void
lp_build_exp2_approx(struct lp_build_context *bld,
LLVMValueRef x,
LLVMValueRef *p_exp2_int_part,
LLVMValueRef *p_frac_part,
LLVMValueRef *p_exp2);
void
lp_build_log2_approx(struct lp_build_context *bld,
LLVMValueRef x,
src/gallium/auxiliary/gallivm/lp_bld_tgsi_action.c
-15
View File
@@ -1057,20 +1057,6 @@ ex2_emit_cpu(
emit_data->args[0]);
}
/* TGSI_OPCODE_EXP (CPU Only) */
static void
exp_emit_cpu(
const struct lp_build_tgsi_action * action,
struct lp_build_tgsi_context * bld_base,
struct lp_build_emit_data * emit_data)
{
lp_build_exp2_approx(&bld_base->base, emit_data->args[0],
&emit_data->output[TGSI_CHAN_X],
&emit_data->output[TGSI_CHAN_Y],
&emit_data->output[TGSI_CHAN_Z]);
emit_data->output[TGSI_CHAN_W] = bld_base->base.one;
}
/* TGSI_OPCODE_F2I (CPU Only) */
static void
f2i_emit_cpu(
@@ -1785,7 +1771,6 @@ lp_set_default_actions_cpu(
bld_base->op_actions[TGSI_OPCODE_CMP].emit = cmp_emit_cpu;
bld_base->op_actions[TGSI_OPCODE_DIV].emit = div_emit_cpu;
bld_base->op_actions[TGSI_OPCODE_EX2].emit = ex2_emit_cpu;
bld_base->op_actions[TGSI_OPCODE_EXP].emit = exp_emit_cpu;
bld_base->op_actions[TGSI_OPCODE_F2I].emit = f2i_emit_cpu;
bld_base->op_actions[TGSI_OPCODE_F2U].emit = f2u_emit_cpu;
bld_base->op_actions[TGSI_OPCODE_FLR].emit = flr_emit_cpu;