fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2025-12-25 02:10:11 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

nir/range_analysis: Add "is finite" range analysis tracking

Browse source 
The obvious changes to nir_search_helpers.h are in a separate commit to
limit the scope of this change.  These additions are really only needed
to support the next commit "nir/range_analysis: Add "is a number" range
analysis tracking".  This reduction in scope is intended to increase the
suitability for stable branches.

No shader-db or fossil-db changes on any Intel platform.

v2: Pack and unpack is_finite.

v3: Split nir_search_helpers.h changes into a separate commit.

v4: Remove assertion intended for the next commit.  Update is_finite
comment for fsign.  Both noticed by Rhys.  Fix is_finite handling for
load_const vectors.  If any element is not finite, set the flag to
false.  This is the same way is_integral is already handled.

v5: Update handling of b2i32.  intBitsToFloat(int(true)) is
1.401298464324817e-45.  Return a value consistent with that.

Fixes: 405de7ccb6 ("nir/range-analysis: Rudimentary value range analysis pass")
Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9108>
This commit is contained in:
Ian Romanick 2020-08-17 15:56:24 -07:00 • committed by Marge Bot
parent 86fb53b1be
commit d4f21b53f2
2 changed files with 69 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

79
src/compiler/nir/nir_range_analysis.c
View file

@ -40,7 +40,7 @@ is_not_negative(enum ssa_ranges r)
static void *
pack_data(const struct ssa_result_range r)
{
return (void *)(uintptr_t)(r.range | r.is_integral << 8);
return (void *)(uintptr_t)(r.range | r.is_integral << 8 | r.is_finite << 9);
}
static struct ssa_result_range
@ -48,7 +48,11 @@ unpack_data(const void *p)
{
const uintptr_t v = (uintptr_t) p;
return (struct ssa_result_range){v & 0xff, (v & 0x0ff00) != 0};
return (struct ssa_result_range){
.range = v & 0xff,
.is_integral = (v & 0x00100) != 0,
.is_finite = (v & 0x00200) != 0
};
}
static void *
@ -103,7 +107,7 @@ analyze_constant(const struct nir_alu_instr *instr, unsigned src,
const nir_load_const_instr *const load =
nir_instr_as_load_const(instr->src[src].src.ssa->parent_instr);
struct ssa_result_range r = { unknown, false };
struct ssa_result_range r = { unknown, false, false };
switch (nir_alu_type_get_base_type(use_type)) {
case nir_type_float: {
@ -113,6 +117,7 @@ analyze_constant(const struct nir_alu_instr *instr, unsigned src,
bool all_zero = true;
r.is_integral = true;
r.is_finite = true;
for (unsigned i = 0; i < num_components; ++i) {
const double v = nir_const_value_as_float(load->value[swizzle[i]],
@ -121,6 +126,9 @@ analyze_constant(const struct nir_alu_instr *instr, unsigned src,
if (floor(v) != v)
r.is_integral = false;
if (!isfinite(v))
r.is_finite = false;
any_zero = any_zero || (v == 0.0);
all_zero = all_zero && (v == 0.0);
min_value = MIN2(min_value, v);
@ -412,13 +420,13 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
STATIC_ASSERT(last_range + 1 == 7);
if (!instr->src[src].src.is_ssa)
return (struct ssa_result_range){unknown, false};
return (struct ssa_result_range){unknown, false, false};
if (nir_src_is_const(instr->src[src].src))
return analyze_constant(instr, src, use_type);
if (instr->src[src].src.ssa->parent_instr->type != nir_instr_type_alu)
return (struct ssa_result_range){unknown, false};
return (struct ssa_result_range){unknown, false, false};
const struct nir_alu_instr *const alu =
nir_instr_as_alu(instr->src[src].src.ssa->parent_instr);
@ -437,7 +445,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
if (use_base_type != src_base_type &&
(use_base_type == nir_type_float ||
src_base_type == nir_type_float)) {
return (struct ssa_result_range){unknown, false};
return (struct ssa_result_range){unknown, false, false};
}
}
@ -445,7 +453,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
if (he != NULL)
return unpack_data(he->data);
struct ssa_result_range r = {unknown, false};
struct ssa_result_range r = {unknown, false, false};
/* ge_zero: ge_zero + ge_zero
*
@ -548,7 +556,13 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
switch (alu->op) {
case nir_op_b2f32:
case nir_op_b2i32:
r = (struct ssa_result_range){ge_zero, alu->op == nir_op_b2f32};
/* b2f32 will generate either 0.0 or 1.0. This case is trivial.
*
* b2i32 will generate either 0x00000000 or 0x00000001. When those bit
* patterns are interpreted as floating point, they are 0.0 and
* 1.401298464324817e-45. The latter is subnormal, but it is finite.
*/
r = (struct ssa_result_range){ge_zero, alu->op == nir_op_b2f32, true};
break;
case nir_op_bcsel: {
@ -558,6 +572,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
analyze_expression(alu, 2, ht, use_type);
r.is_integral = left.is_integral && right.is_integral;
r.is_finite = left.is_finite && right.is_finite;
/* le_zero: bcsel(<any>, le_zero, lt_zero)
* | bcsel(<any>, eq_zero, lt_zero)
@ -623,6 +638,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r = analyze_expression(alu, 0, ht, nir_alu_src_type(alu, 0));
r.is_integral = true;
r.is_finite = true;
if (r.range == unknown && alu->op == nir_op_u2f32)
r.range = ge_zero;
@ -679,6 +695,9 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r.is_integral = r.is_integral && is_not_negative(r.range);
r.range = table[r.range];
/* Various cases can result in NaN, so assume the worst. */
r.is_finite = false;
break;
}
@ -690,6 +709,13 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r.is_integral = left.is_integral && right.is_integral;
/* This is conservative. It may be possible to determine that the
* result must be finite in more cases, but it would take some effort to
* work out all the corners. For example, fmax({lt_zero, finite},
* {lt_zero}) should result in {lt_zero, finite}.
*/
r.is_finite = left.is_finite && right.is_finite;
/* gt_zero: fmax(gt_zero, *)
* | fmax(*, gt_zero) # Treat fmax as commutative
* ;
@ -755,6 +781,13 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r.is_integral = left.is_integral && right.is_integral;
/* This is conservative. It may be possible to determine that the
* result must be finite in more cases, but it would take some effort to
* work out all the corners. For example, fmin({gt_zero, finite},
* {gt_zero}) should result in {gt_zero, finite}.
*/
r.is_finite = left.is_finite && right.is_finite;
/* lt_zero: fmin(lt_zero, *)
* | fmin(*, lt_zero) # Treat fmin as commutative
* ;
@ -838,7 +871,8 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
case nir_op_frcp:
r = (struct ssa_result_range){
analyze_expression(alu, 0, ht, nir_alu_src_type(alu, 0)).range,
false
false,
false /* Various cases can result in NaN, so assume the worst. */
};
break;
@ -856,6 +890,9 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
const struct ssa_result_range left =
analyze_expression(alu, 0, ht, nir_alu_src_type(alu, 0));
/* fsat(NaN) = 0. */
r.is_finite = true;
switch (left.range) {
case le_zero:
case lt_zero:
@ -884,13 +921,14 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
case nir_op_fsign:
r = (struct ssa_result_range){
analyze_expression(alu, 0, ht, nir_alu_src_type(alu, 0)).range,
true
true,
true /* fsign is -1, 0, or 1, even for NaN, so it must be finite. */
};
break;
case nir_op_fsqrt:
case nir_op_frsq:
r = (struct ssa_result_range){ge_zero, false};
r = (struct ssa_result_range){ge_zero, false, false};
break;
case nir_op_ffloor: {
@ -899,6 +937,11 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r.is_integral = true;
/* In IEEE 754, floor(NaN) is NaN, and floor(±Inf) is ±Inf. See
* https://pubs.opengroup.org/onlinepubs/9699919799.2016edition/functions/floor.html
*/
r.is_finite = left.is_finite;
if (left.is_integral || left.range == le_zero || left.range == lt_zero)
r.range = left.range;
else if (left.range == ge_zero || left.range == gt_zero)
@ -915,6 +958,11 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r.is_integral = true;
/* In IEEE 754, ceil(NaN) is NaN, and ceil(±Inf) is ±Inf. See
* https://pubs.opengroup.org/onlinepubs/9699919799.2016edition/functions/ceil.html
*/
r.is_finite = left.is_finite;
if (left.is_integral || left.range == ge_zero || left.range == gt_zero)
r.range = left.range;
else if (left.range == le_zero || left.range == lt_zero)
@ -931,6 +979,11 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r.is_integral = true;
/* In IEEE 754, trunc(NaN) is NaN, and trunc(±Inf) is ±Inf. See
* https://pubs.opengroup.org/onlinepubs/9699919799.2016edition/functions/trunc.html
*/
r.is_finite = left.is_finite;
if (left.is_integral)
r.range = left.range;
else if (left.range == ge_zero || left.range == gt_zero)
@ -954,7 +1007,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
case nir_op_ult:
case nir_op_uge:
/* Boolean results are 0 or -1. */
r = (struct ssa_result_range){le_zero, false};
r = (struct ssa_result_range){le_zero, false, false};
break;
case nir_op_fpow: {
@ -1073,7 +1126,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
}
default:
r = (struct ssa_result_range){unknown, false};
r = (struct ssa_result_range){unknown, false, false};
break;
}

3
src/compiler/nir/nir_range_analysis.h
View file

@ -39,6 +39,9 @@ struct ssa_result_range {
/** A floating-point value that can only have integer values. */
bool is_integral;
/** Is the value known to be a finite number? */
bool is_finite;
};
#ifdef __cplusplus