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gk104/ir: Use the new rcp/rsq in library

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[imirkin: add a few more "long" prefixes to safen things up]
Acked-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: 19.0 <mesa-stable@lists.freedesktop.org>

(cherry picked from commit 12669d2970)
This commit is contained in:
Karol Herbst 2017-08-14 23:55:25 +02:00 • committed by Dylan Baker
parent 81810fa5db
commit c96d433105
3 changed files with 334 additions and 15 deletions
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203
src/gallium/drivers/nouveau/codegen/lib/gk104.asm
View file

@ -543,6 +543,8 @@ $p2 suldgb b32 $r3 cg zero u8 g[$r4d] $r2 $p0
$p1 suldgb b32 $r3 cv zero u8 g[$r4d] $r2 $p0
long mov b32 $r3 0x3f800000
long nop
sched 0x00 0x00 0x00 0x00 0x00 0x00 0x00
long nop
long ret
@ -554,7 +556,144 @@ long ret
// SIZE: 9 * 8 bytes
//
gk104_rcp_f64:
long nop
// Step 1: classify input according to exponent and value, and calculate
// result for 0/inf/nan. $r2 holds the exponent value, which starts at
// bit 52 (bit 20 of the upper half) and is 11 bits in length
ext u32 $r2 $r1 0xb14
add b32 $r3 $r2 0xffffffff
joinat #rcp_rejoin
// We want to check whether the exponent is 0 or 0x7ff (i.e. NaN, inf,
// denorm, or 0). Do this by substracting 1 from the exponent, which will
// mean that it's > 0x7fd in those cases when doing unsigned comparison
set $p0 0x1 gt u32 $r3 0x7fd
// $r3: 0 for norms, 0x36 for denorms, -1 for others
long mov b32 $r3 0x0
sched 0x2f 0x04 0x2d 0x2b 0x2f 0x28 0x28
join (not $p0) nop
// Process all special values: NaN, inf, denorm, 0
mov b32 $r3 0xffffffff
// A number is NaN if its abs value is greater than or unordered with inf
set $p0 0x1 gtu f64 abs $r0d 0x7ff0000000000000
(not $p0) bra #rcp_inf_or_denorm_or_zero
// NaN -> NaN, the next line sets the "quiet" bit of the result. This
// behavior is both seen on the CPU and the blob
join or b32 $r1 $r1 0x80000
rcp_inf_or_denorm_or_zero:
and b32 $r4 $r1 0x7ff00000
// Other values with nonzero in exponent field should be inf
set $p0 0x1 eq s32 $r4 0x0
sched 0x2b 0x04 0x2f 0x2d 0x2b 0x2f 0x20
$p0 bra #rcp_denorm_or_zero
// +/-Inf -> +/-0
xor b32 $r1 $r1 0x7ff00000
join mov b32 $r0 0x0
rcp_denorm_or_zero:
set $p0 0x1 gtu f64 abs $r0d 0x0
$p0 bra #rcp_denorm
// +/-0 -> +/-Inf
join or b32 $r1 $r1 0x7ff00000
rcp_denorm:
// non-0 denorms: multiply with 2^54 (the 0x36 in $r3), join with norms
mul rn f64 $r0d $r0d 0x4350000000000000
sched 0x2f 0x28 0x2b 0x28 0x28 0x04 0x28
join mov b32 $r3 0x36
rcp_rejoin:
// All numbers with -1 in $r3 have their result ready in $r0d, return them
// others need further calculation
set $p0 0x1 lt s32 $r3 0x0
$p0 bra #rcp_end
// Step 2: Before the real calculation goes on, renormalize the values to
// range [1, 2) by setting exponent field to 0x3ff (the exponent of 1)
// result in $r6d. The exponent will be recovered later.
ext u32 $r2 $r1 0xb14
and b32 $r7 $r1 0x800fffff
add b32 $r7 $r7 0x3ff00000
long mov b32 $r6 $r0
sched 0x2b 0x04 0x28 0x28 0x2a 0x2b 0x2e
// Step 3: Convert new value to float (no overflow will occur due to step
// 2), calculate rcp and do newton-raphson step once
cvt rz f32 $r5 f64 $r6d
long rcp f32 $r4 $r5
mov b32 $r0 0xbf800000
fma rn f32 $r5 $r4 $r5 $r0
fma rn f32 $r0 neg $r4 $r5 $r4
// Step 4: convert result $r0 back to double, do newton-raphson steps
cvt f64 $r0d f32 $r0
cvt f64 $r6d neg f64 $r6d
sched 0x2e 0x29 0x29 0x29 0x29 0x29 0x29
cvt f64 $r8d f32 0x3f800000
// 4 Newton-Raphson Steps, tmp in $r4d, result in $r0d
// The formula used here (and above) is:
// RCP_{n + 1} = 2 * RCP_{n} - x * RCP_{n} * RCP_{n}
// The following code uses 2 FMAs for each step, and it will basically
// looks like:
// tmp = -src * RCP_{n} + 1
// RCP_{n + 1} = RCP_{n} * tmp + RCP_{n}
fma rn f64 $r4d $r6d $r0d $r8d
fma rn f64 $r0d $r0d $r4d $r0d
fma rn f64 $r4d $r6d $r0d $r8d
fma rn f64 $r0d $r0d $r4d $r0d
fma rn f64 $r4d $r6d $r0d $r8d
fma rn f64 $r0d $r0d $r4d $r0d
sched 0x29 0x20 0x28 0x28 0x28 0x28 0x28
fma rn f64 $r4d $r6d $r0d $r8d
fma rn f64 $r0d $r0d $r4d $r0d
// Step 5: Exponent recovery and final processing
// The exponent is recovered by adding what we added to the exponent.
// Suppose we want to calculate rcp(x), but we have rcp(cx), then
// rcp(x) = c * rcp(cx)
// The delta in exponent comes from two sources:
// 1) The renormalization in step 2. The delta is:
// 0x3ff - $r2
// 2) (For the denorm input) The 2^54 we multiplied at rcp_denorm, stored
// in $r3
// These 2 sources are calculated in the first two lines below, and then
// added to the exponent extracted from the result above.
// Note that after processing, the new exponent may >= 0x7ff (inf)
// or <= 0 (denorm). Those cases will be handled respectively below
subr b32 $r2 $r2 0x3ff
long add b32 $r4 $r2 $r3
ext u32 $r3 $r1 0xb14
// New exponent in $r3
long add b32 $r3 $r3 $r4
add b32 $r2 $r3 0xffffffff
sched 0x28 0x2b 0x28 0x2b 0x28 0x28 0x2b
// (exponent-1) < 0x7fe (unsigned) means the result is in norm range
// (same logic as in step 1)
set $p0 0x1 lt u32 $r2 0x7fe
(not $p0) bra #rcp_result_inf_or_denorm
// Norms: convert exponents back and return
shl b32 $r4 $r4 clamp 0x14
long add b32 $r1 $r4 $r1
bra #rcp_end
rcp_result_inf_or_denorm:
// New exponent >= 0x7ff means that result is inf
set $p0 0x1 ge s32 $r3 0x7ff
(not $p0) bra #rcp_result_denorm
sched 0x20 0x25 0x28 0x2b 0x23 0x25 0x2f
// Infinity
and b32 $r1 $r1 0x80000000
long mov b32 $r0 0x0
add b32 $r1 $r1 0x7ff00000
bra #rcp_end
rcp_result_denorm:
// Denorm result comes from huge input. The greatest possible fp64, i.e.
// 0x7fefffffffffffff's rcp is 0x0004000000000000, 1/4 of the smallest
// normal value. Other rcp result should be greater than that. If we
// set the exponent field to 1, we can recover the result by multiplying
// it with 1/2 or 1/4. 1/2 is used if the "exponent" $r3 is 0, otherwise
// 1/4 ($r3 should be -1 then). This is quite tricky but greatly simplifies
// the logic here.
set $p0 0x1 ne u32 $r3 0x0
and b32 $r1 $r1 0x800fffff
// 0x3e800000: 1/4
$p0 cvt f64 $r6d f32 0x3e800000
sched 0x2f 0x28 0x2c 0x2e 0x2a 0x20 0x27
// 0x3f000000: 1/2
(not $p0) cvt f64 $r6d f32 0x3f000000
add b32 $r1 $r1 0x00100000
mul rn f64 $r0d $r0d $r6d
rcp_end:
long ret
// RSQ F64: Newton Raphson rsqrt(x): r_{i+1} = r_i * (1.5 - 0.5 * x * r_i * r_i)
@ -565,7 +704,67 @@ gk104_rcp_f64:
// SIZE: 14 * 8 bytes
//
gk104_rsq_f64:
long nop
// Before getting initial result rsqrt64h, two special cases should be
// handled first.
// 1. NaN: set the highest bit in mantissa so it'll be surely recognized
// as NaN in rsqrt64h
set $p0 0x1 gtu f64 abs $r0d 0x7ff0000000000000
$p0 or b32 $r1 $r1 0x00080000
and b32 $r2 $r1 0x7fffffff
sched 0x27 0x20 0x28 0x2c 0x25 0x28 0x28
// 2. denorms and small normal values: using their original value will
// lose precision either at rsqrt64h or the first step in newton-raphson
// steps below. Take 2 as a threshold in exponent field, and multiply
// with 2^54 if the exponent is smaller or equal. (will multiply 2^27
// to recover in the end)
ext u32 $r3 $r1 0xb14
set $p1 0x1 le u32 $r3 0x2
long or b32 $r2 $r0 $r2
$p1 mul rn f64 $r0d $r0d 0x4350000000000000
rsqrt64h $r5 $r1
// rsqrt64h will give correct result for 0/inf/nan, the following logic
// checks whether the input is one of those (exponent is 0x7ff or all 0
// except for the sign bit)
set b32 $r6 ne u32 $r3 0x7ff
long and b32 $r2 $r2 $r6
sched 0x28 0x2b 0x20 0x27 0x28 0x2e 0x28
set $p0 0x1 ne u32 $r2 0x0
$p0 bra #rsq_norm
// For 0/inf/nan, make sure the sign bit agrees with input and return
and b32 $r1 $r1 0x80000000
long mov b32 $r0 0x0
long or b32 $r1 $r1 $r5
long ret
rsq_norm:
// For others, do 4 Newton-Raphson steps with the formula:
// RSQ_{n + 1} = RSQ_{n} * (1.5 - 0.5 * x * RSQ_{n} * RSQ_{n})
// In the code below, each step is written as:
// tmp1 = 0.5 * x * RSQ_{n}
// tmp2 = -RSQ_{n} * tmp1 + 0.5
// RSQ_{n + 1} = RSQ_{n} * tmp2 + RSQ_{n}
long mov b32 $r4 0x0
sched 0x2f 0x29 0x29 0x29 0x29 0x29 0x29
// 0x3f000000: 1/2
cvt f64 $r8d f32 0x3f000000
mul rn f64 $r2d $r0d $r8d
mul rn f64 $r0d $r2d $r4d
fma rn f64 $r6d neg $r4d $r0d $r8d
fma rn f64 $r4d $r4d $r6d $r4d
mul rn f64 $r0d $r2d $r4d
fma rn f64 $r6d neg $r4d $r0d $r8d
sched 0x29 0x29 0x29 0x29 0x29 0x29 0x29
fma rn f64 $r4d $r4d $r6d $r4d
mul rn f64 $r0d $r2d $r4d
fma rn f64 $r6d neg $r4d $r0d $r8d
fma rn f64 $r4d $r4d $r6d $r4d
mul rn f64 $r0d $r2d $r4d
fma rn f64 $r6d neg $r4d $r0d $r8d
fma rn f64 $r4d $r4d $r6d $r4d
sched 0x29 0x20 0x28 0x2e 0x00 0x00 0x00
// Multiply 2^27 to result for small inputs to recover
$p1 mul rn f64 $r4d $r4d 0x41a0000000000000
long mov b32 $r1 $r5
long mov b32 $r0 $r4
long ret
//

144
src/gallium/drivers/nouveau/codegen/lib/gk104.asm.h
View file

@ -481,12 +481,132 @@ uint64_t gk104_builtin_code[] = {
0xd40040000840c785,
0x18fe00000000dde2,
0x4000000000001de4,
0x9000000000001de7,
/* 0x0f08: gk104_rcp_f64 */
0x2000000000000007,
0x4000000000001de4,
0x9000000000001de7,
/* 0x0f18: gk104_rsq_f64 */
0x4000000000001de4,
/* 0x0f18: gk104_rcp_f64 */
0x7000c02c50109c03,
0x0bfffffffc20dc02,
0x6000000280000007,
0x1a0ec01ff431dc03,
0x180000000000dde2,
0x228282f2b2d042f7,
0x40000000000021f4,
0x1bfffffffc00dde2,
0x1e0edffc0001dc81,
0x40000000200021e7,
0x3800200000105c52,
/* 0x0f70: rcp_inf_or_denorm_or_zero */
0x39ffc00000111c02,
0x190e0000fc41dc23,
0x2202f2b2d2f042b7,
0x40000000400001e7,
0x39ffc00000105c82,
0x1800000000001df2,
/* 0x0fa0: rcp_denorm_or_zero */
0x1e0ec0000001dc81,
0x40000000200001e7,
0x39ffc00000105c52,
/* 0x0fb8: rcp_denorm */
0x5000d0d400001c01,
0x2280428282b282f7,
0x18000000d800ddf2,
/* 0x0fd0: rcp_rejoin */
0x188e0000fc31dc23,
0x40000006000001e7,
0x7000c02c50109c03,
0x3a003ffffc11dc02,
0x08ffc0000071dc02,
0x2800000000019de4,
0x22e2b2a2828042b7,
0x1006000019a15c04,
0xc800000010511c00,
0x1afe000000001de2,
0x3000000014415c00,
0x3008000014401e00,
0x1000000001301c04,
0x1000000019b19d04,
0x22929292929292e7,
0x1000cfe001321c04,
0x2010000000611c01,
0x2000000010001c01,
0x2010000000611c01,
0x2000000010001c01,
0x2010000000611c01,
0x2000000010001c01,
0x2282828282820297,
0x2010000000611c01,
0x2000000010001c01,
0x0800000ffc209e02,
0x480000000c211c03,
0x7000c02c5010dc03,
0x480000001030dc03,
0x0bfffffffc309c02,
0x22b28282b282b287,
0x188ec01ff821dc03,
0x40000000600021e7,
0x6000c00050411c03,
0x4800000004405c03,
0x40000001c0001de7,
/* 0x10f0: rcp_result_inf_or_denorm */
0x1b0ec01ffc31dc23,
0x40000000a00021e7,
0x22f25232b2825207,
0x3a00000000105c02,
0x1800000000001de2,
0x09ffc00000105c02,
0x40000000e0001de7,
/* 0x1128: rcp_result_denorm */
0x1a8e0000fc31dc03,
0x3a003ffffc105c02,
0x1000cfa001318004,
0x227202a2e2c282f7,
0x1000cfc00131a004,
0x0800400000105c02,
0x5000000018001c01,
/* 0x1160: rcp_end */
0x9000000000001de7,
/* 0x1168: gk104_rsq_f64 */
0x1e0edffc0001dc81,
0x3800200000104042,
0x39fffffffc109c02,
0x22828252c2820277,
0x7000c02c5010dc03,
0x198ec0000833dc03,
0x6800000008009c43,
0x5000d0d400000401,
0xc80000001c115c00,
0x128ec01ffc319c03,
0x6800000018209c03,
0x2282e2827202b287,
0x1a8e0000fc21dc03,
0x40000000800001e7,
0x3a00000000105c02,
0x1800000000001de2,
0x6800000014105c43,
0x9000000000001de7,
/* 0x11f8: rsq_norm */
0x1800000000011de2,
0x22929292929292f7,
0x1000cfc001321c04,
0x5000000020009c01,
0x5000000010201c01,
0x2010000000419e01,
0x2008000018411c01,
0x5000000010201c01,
0x2010000000419e01,
0x2292929292929297,
0x2008000018411c01,
0x5000000010201c01,
0x2010000000419e01,
0x2008000018411c01,
0x5000000010201c01,
0x2010000000419e01,
0x2008000018411c01,
0x20000002e2820297,
0x5000d06800410401,
0x2800000014005de4,
0x2800000010001de4,
0x9000000000001de7,
0xc800000003f01cc5,
0x2c00000100005c04,
@ -495,7 +615,7 @@ uint64_t gk104_builtin_code[] = {
0x680100000c1fdc03,
0x4000000a60001c47,
0x180000004000dde2,
/* 0x0f60: spill_cfstack */
/* 0x12e0: spill_cfstack */
0x78000009c0000007,
0x0c0000000430dd02,
0x4003ffffa0001ca7,
@ -543,14 +663,14 @@ uint64_t gk104_builtin_code[] = {
0x4000000100001ea7,
0x480100000c001c03,
0x0800000000105c42,
/* 0x10d8: shared_loop */
/* 0x1458: shared_loop */
0xc100000000309c85,
0x9400000500009c85,
0x0c00000010001d02,
0x0800000000105d42,
0x0c0000001030dd02,
0x4003ffff40001ca7,
/* 0x1108: shared_done */
/* 0x1488: shared_done */
0x2800406420001de4,
0x2800406430005de4,
0xe000000000001c45,
@ -564,7 +684,7 @@ uint64_t gk104_builtin_code[] = {
0x480000000c209c03,
0x4801000008001c03,
0x0800000000105c42,
/* 0x1170: search_cstack */
/* 0x14f0: search_cstack */
0x280040646000dde4,
0x8400000020009f05,
0x190ec0002821dc03,
@ -573,17 +693,17 @@ uint64_t gk104_builtin_code[] = {
0x0800000000105c42,
0x0c0000004030dd02,
0x00029dff0ffc5cbf,
/* 0x11b0: entry_found */
/* 0x1530: entry_found */
0x8400000000009f85,
0x2800406400001de4,
0x2800406410005de4,
0x9400000010009c85,
0x4000000000001df4,
/* 0x11d8: end_exit */
/* 0x1558: end_exit */
0x9800000003ffdcc5,
0xd000000000008007,
0xa000000000004007,
/* 0x11f0: end_cont */
/* 0x1570: end_cont */
0xd000000000008007,
0x3400c3fffc201c04,
0xc000000003f01ec5,
@ -593,6 +713,6 @@ uint64_t gk104_builtin_code[] = {
uint64_t gk104_builtin_offsets[] = {
0x0000000000000000,
0x00000000000000f0,
0x0000000000000f08,
0x0000000000000f18,
0x0000000000001168,
};

2
src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
View file

@ -129,7 +129,7 @@ NVC0LegalizeSSA::handleRCPRSQ(Instruction *i)
bld.mkSplit(src, 4, i->getSrc(0));
int chip = prog->getTarget()->getChipset();
if (chip >= NVISA_GK20A_CHIPSET && chip < NVISA_GM107_CHIPSET) {
if (chip >= NVISA_GK104_CHIPSET && chip < NVISA_GM107_CHIPSET) {
handleRCPRSQLib(i, src);
return;
}