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nir/range_analysis: Add "is a number" range analysis tracking

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This commit is necessary to support "nir/range_analysis: Fix analysis of
fmin and fmax with NaN".

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

v2: Pack and unpack is_a_number.

v3: Don't set is_a_number of integer constants.  The bit pattern might
be NaN.

v4: 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
2020-07-02 18:18:09 -07:00
committed by Marge Bot
parent d4f21b53f2
commit aa5d38decd
3 changed files with 94 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/compiler/nir/nir_range_analysis.c
+83 -13
View File
@@ -37,10 +37,17 @@ is_not_negative(enum ssa_ranges r)
return r == gt_zero || r == ge_zero || r == eq_zero;
}
static bool
is_not_zero(enum ssa_ranges r)
{
return r == gt_zero || r == lt_zero || r == ne_zero;
}
static void *
pack_data(const struct ssa_result_range r)
{
return (void *)(uintptr_t)(r.range | r.is_integral << 8 | r.is_finite << 9);
return (void *)(uintptr_t)(r.range | r.is_integral << 8 | r.is_finite << 9 |
r.is_a_number << 10);
}
static struct ssa_result_range
@@ -51,7 +58,8 @@ unpack_data(const void *p)
return (struct ssa_result_range){
.range = v & 0xff,
.is_integral = (v & 0x00100) != 0,
.is_finite = (v & 0x00200) != 0
.is_finite = (v & 0x00200) != 0,
.is_a_number = (v & 0x00400) != 0
};
}
@@ -107,7 +115,7 @@ 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, false };
struct ssa_result_range r = { unknown, false, false, false };
switch (nir_alu_type_get_base_type(use_type)) {
case nir_type_float: {
@@ -117,6 +125,7 @@ analyze_constant(const struct nir_alu_instr *instr, unsigned src,
bool all_zero = true;
r.is_integral = true;
r.is_a_number = true;
r.is_finite = true;
for (unsigned i = 0; i < num_components; ++i) {
@@ -126,6 +135,9 @@ analyze_constant(const struct nir_alu_instr *instr, unsigned src,
if (floor(v) != v)
r.is_integral = false;
if (isnan(v))
r.is_a_number = false;
if (!isfinite(v))
r.is_finite = false;
@@ -420,13 +432,13 @@ 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, false};
return (struct ssa_result_range){unknown, false, 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, false};
return (struct ssa_result_range){unknown, false, false, false};
const struct nir_alu_instr *const alu =
nir_instr_as_alu(instr->src[src].src.ssa->parent_instr);
@@ -445,7 +457,7 @@ 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, false};
return (struct ssa_result_range){unknown, false, false, false};
}
}
@@ -453,7 +465,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
if (he != NULL)
return unpack_data(he->data);
struct ssa_result_range r = {unknown, false, false};
struct ssa_result_range r = {unknown, false, false, false};
/* ge_zero: ge_zero + ge_zero
*
@@ -560,9 +572,10 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
*
* 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.
* 1.401298464324817e-45. The latter is subnormal, but it is finite and
* a number.
*/
r = (struct ssa_result_range){ge_zero, alu->op == nir_op_b2f32, true};
r = (struct ssa_result_range){ge_zero, alu->op == nir_op_b2f32, true, true};
break;
case nir_op_bcsel: {
@@ -572,6 +585,20 @@ 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;
/* This could be better, but it would require a lot of work. For
* example, the result of the following is a number:
*
* bcsel(a > 0.0, a, 38.6)
*
* If the result of 'a > 0.0' is true, then the use of 'a' in the true
* part of the bcsel must be a number.
*
* Other cases are even more challenging.
*
* bcsel(a > 0.5, a - 0.5, 0.0)
*/
r.is_a_number = left.is_a_number && right.is_a_number;
r.is_finite = left.is_finite && right.is_finite;
/* le_zero: bcsel(<any>, le_zero, lt_zero)
@@ -638,6 +665,7 @@ 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_a_number = true;
r.is_finite = true;
if (r.range == unknown && alu->op == nir_op_u2f32)
@@ -675,6 +703,13 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r.is_integral = left.is_integral && right.is_integral;
r.range = fadd_table[left.range][right.range];
/* X + Y is NaN if either operand is NaN or if one operand is +Inf and
* the other is -Inf. If neither operand is NaN and at least one of the
* operands is finite, then the result cannot be NaN.
*/
r.is_a_number = left.is_a_number && right.is_a_number &&
(left.is_finite || right.is_finite);
break;
}
@@ -698,6 +733,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
/* Various cases can result in NaN, so assume the worst. */
r.is_finite = false;
r.is_a_number = false;
break;
}
@@ -716,6 +752,9 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
*/
r.is_finite = left.is_finite && right.is_finite;
/* If one source is NaN, fmax always picks the other source. */
r.is_a_number = left.is_a_number || right.is_a_number;
/* gt_zero: fmax(gt_zero, *)
* | fmax(*, gt_zero) # Treat fmax as commutative
* ;
@@ -788,6 +827,9 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
*/
r.is_finite = left.is_finite && right.is_finite;
/* If one source is NaN, fmin always picks the other source. */
r.is_a_number = left.is_a_number || right.is_a_number;
/* lt_zero: fmin(lt_zero, *)
* | fmin(*, lt_zero) # Treat fmin as commutative
* ;
@@ -865,6 +907,15 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
} else
r.range = fmul_table[left.range][right.range];
/* Mulitpliation produces NaN for X * NaN and for 0 * ±Inf. If both
* operands are numbers and either both are finite or one is finite and
* the other cannot be zero, then the result must be a number.
*/
r.is_a_number = (left.is_a_number && right.is_a_number) &&
((left.is_finite && right.is_finite) ||
(!is_not_zero(left.range) && right.is_finite) ||
(left.is_finite && !is_not_zero(right.range)));
break;
}
@@ -872,7 +923,8 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r = (struct ssa_result_range){
analyze_expression(alu, 0, ht, nir_alu_src_type(alu, 0)).range,
false,
false /* Various cases can result in NaN, so assume the worst. */
false, /* Various cases can result in NaN, so assume the worst. */
false /* " " " " " " " " " " */
};
break;
@@ -891,6 +943,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
analyze_expression(alu, 0, ht, nir_alu_src_type(alu, 0));
/* fsat(NaN) = 0. */
r.is_a_number = true;
r.is_finite = true;
switch (left.range) {
@@ -922,13 +975,14 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r = (struct ssa_result_range){
analyze_expression(alu, 0, ht, nir_alu_src_type(alu, 0)).range,
true,
true, /* fsign is -1, 0, or 1, even for NaN, so it must be a number. */
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, false};
r = (struct ssa_result_range){ge_zero, false, false, false};
break;
case nir_op_ffloor: {
@@ -940,6 +994,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
/* 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_a_number = left.is_a_number;
r.is_finite = left.is_finite;
if (left.is_integral || left.range == le_zero || left.range == lt_zero)
@@ -961,6 +1016,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
/* 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_a_number = left.is_a_number;
r.is_finite = left.is_finite;
if (left.is_integral || left.range == ge_zero || left.range == gt_zero)
@@ -982,6 +1038,7 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
/* 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_a_number = left.is_a_number;
r.is_finite = left.is_finite;
if (left.is_integral)
@@ -1007,7 +1064,7 @@ 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, false};
r = (struct ssa_result_range){le_zero, false, true, false};
break;
case nir_op_fpow: {
@@ -1072,6 +1129,10 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r.is_integral = left.is_integral && right.is_integral &&
is_not_negative(right.range);
r.range = table[left.range][right.range];
/* Various cases can result in NaN, so assume the worst. */
r.is_a_number = false;
break;
}
@@ -1086,6 +1147,9 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r.is_integral = first.is_integral && second.is_integral &&
third.is_integral;
/* Various cases can result in NaN, so assume the worst. */
r.is_a_number = false;
enum ssa_ranges fmul_range;
if (first.range != eq_zero && nir_alu_srcs_equal(alu, alu, 0, 1)) {
@@ -1114,6 +1178,9 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
r.is_integral = first.is_integral && second.is_integral &&
third.is_integral;
/* Various cases can result in NaN, so assume the worst. */
r.is_a_number = false;
/* Decompose the flrp to first + third * (second + -first) */
const enum ssa_ranges inner_fadd_range =
fadd_table[second.range][fneg_table[first.range]];
@@ -1126,13 +1193,16 @@ analyze_expression(const nir_alu_instr *instr, unsigned src,
}
default:
r = (struct ssa_result_range){unknown, false, false};
r = (struct ssa_result_range){unknown, false, false, false};
break;
}
if (r.range == eq_zero)
r.is_integral = true;
/* Just like isfinite(), the is_finite flag implies the value is a number. */
assert((int) r.is_finite <= (int) r.is_a_number);
_mesa_hash_table_insert(ht, pack_key(alu, use_type), pack_data(r));
return r;
}
src/compiler/nir/nir_range_analysis.h
+3
View File
@@ -40,6 +40,9 @@ struct ssa_result_range {
/** A floating-point value that can only have integer values. */
bool is_integral;
/** A floating-point value that cannot be NaN. */
bool is_a_number;
/** Is the value known to be a finite number? */
bool is_finite;
};
src/compiler/nir/nir_search_helpers.h
+8
View File
@@ -494,4 +494,12 @@ is_not_zero(struct hash_table *ht, const nir_alu_instr *instr, unsigned src,
return v.range == lt_zero || v.range == gt_zero || v.range == ne_zero;
}
static inline bool
is_a_number(struct hash_table *ht, const nir_alu_instr *instr, unsigned src,
UNUSED unsigned num_components, UNUSED const uint8_t *swizzle)
{
const struct ssa_result_range v = nir_analyze_range(ht, instr, src);
return v.is_a_number;
}
#endif /* _NIR_SEARCH_ */