[Mesa-dev] [PATCH 10/13] gm107/ir: add fp64 rsq
Karol Herbst
kherbst at redhat.com
Sun Jul 15 18:15:50 UTC 2018
Signed-off-by: Karol Herbst <kherbst at redhat.com>
---
.../drivers/nouveau/codegen/lib/gm107.asm | 78 ++++++++++++++++++-
.../drivers/nouveau/codegen/lib/gm107.asm.h | 51 +++++++++++-
.../nouveau/codegen/nv50_ir_lowering_nvc0.cpp | 2 +-
3 files changed, 128 insertions(+), 3 deletions(-)
diff --git a/src/gallium/drivers/nouveau/codegen/lib/gm107.asm b/src/gallium/drivers/nouveau/codegen/lib/gm107.asm
index 595d9dc5d41..faee0218d18 100644
--- a/src/gallium/drivers/nouveau/codegen/lib/gm107.asm
+++ b/src/gallium/drivers/nouveau/codegen/lib/gm107.asm
@@ -269,8 +269,84 @@ rcp_result_denorm:
rcp_end:
ret
+// RSQ F64
+//
+// INPUT: $r0d
+// OUTPUT: $r0d
+// CLOBBER: $r2 - $r9, $p0 - $p1
+//
gm107_rsq_f64:
- sched (st 0x0) (st 0x0) (st 0x0)
+ // 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
+ sched (st 0xd wr 0x0 wt 0x3f) (st 0xd wt 0x1) (st 0xd)
+ dsetp gtu and $p0 1 abs $r0 0x7ff0000000000000 1
+ $p0 lop32i or $r1 $r1 0x00080000
+ lop32i and $r2 $r1 0x7fffffff
+ // 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)
+ sched (st 0xd) (st 0xd) (st 0xd)
+ bfe u32 $r3 $r1 0xb14
+ isetp le u32 and $p1 1 $r3 0x2 1
+ lop or 1 $r2 $r0 $r2
+ sched (st 0xd wr 0x0) (st 0xd wr 0x0 wt 0x1) (st 0xd)
+ $p1 dmul $r0 $r0 0x4350000000000000
+ mufu rsq64h $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)
+ iset ne u32 and $r6 $r3 0x7ff 1
+ sched (st 0xd) (st 0xd) (st 0xd)
+ lop and 1 $r2 $r2 $r6
+ isetp ne u32 and $p0 1 $r2 0x0 1
+ $p0 bra #rsq_norm
+ // For 0/inf/nan, make sure the sign bit agrees with input and return
+ sched (st 0xd) (st 0xd) (st 0xd wt 0x1)
+ lop32i and $r1 $r1 0x80000000
+ mov $r0 0x0 0xf
+ lop or 1 $r1 $r1 $r5
+ sched (st 0xd) (st 0xf) (st 0xf)
+ ret
+ nop 0
+ nop 0
+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}
+ sched (st 0xd) (st 0xd wr 0x1) (st 0xd wr 0x1 rd 0x0 wt 0x3)
+ mov $r4 0x0 0xf
+ // 0x3f000000: 1/2
+ f2f f32 f64 $r8 0x3f000000
+ dmul $r2 $r0 $r8
+ sched (st 0xd wr 0x0 wt 0x3) (st 0xd wr 0x0 wt 0x1) (st 0xd wr 0x0 wt 0x1)
+ dmul $r0 $r2 $r4
+ dfma $r6 $r0 neg $r4 $r8
+ dfma $r4 $r4 $r6 $r4
+ sched (st 0xd wr 0x0 wt 0x1) (st 0xd wr 0x0 wt 0x1) (st 0xd wr 0x0 wt 0x1)
+ dmul $r0 $r2 $r4
+ dfma $r6 $r0 neg $r4 $r8
+ dfma $r4 $r4 $r6 $r4
+ sched (st 0xd wr 0x0 wt 0x1) (st 0xd wr 0x0 wt 0x1) (st 0xd wr 0x0 wt 0x1)
+ dmul $r0 $r2 $r4
+ dfma $r6 $r0 neg $r4 $r8
+ dfma $r4 $r4 $r6 $r4
+ sched (st 0xd wr 0x0 wt 0x1) (st 0xd wr 0x0 wt 0x1) (st 0xd wr 0x0 wt 0x1)
+ dmul $r0 $r2 $r4
+ dfma $r6 $r0 neg $r4 $r8
+ dfma $r4 $r4 $r6 $r4
+ // Multiply 2^27 to result for small inputs to recover
+ sched (st 0xd wr 0x0 wt 0x1) (st 0xd wt 0x1) (st 0xd)
+ $p1 dmul $r4 $r4 0x41a0000000000000
+ mov $r1 $r5 0xf
+ mov $r0 $r4 0xf
+ sched (st 0xd) (st 0xf) (st 0xf)
ret
nop 0
nop 0
diff --git a/src/gallium/drivers/nouveau/codegen/lib/gm107.asm.h b/src/gallium/drivers/nouveau/codegen/lib/gm107.asm.h
index 206d01bde83..8eb27bbac99 100644
--- a/src/gallium/drivers/nouveau/codegen/lib/gm107.asm.h
+++ b/src/gallium/drivers/nouveau/codegen/lib/gm107.asm.h
@@ -182,7 +182,56 @@ uint64_t gm107_builtin_code[] = {
/* 0x0558: rcp_end */
0xe32000000007000f,
/* 0x0560: gm107_rsq_f64 */
- 0x001f8000fc0007e0,
+ 0x001fb401fda1ff0d,
+ 0x368c03fff0070087,
+ 0x0420008000000101,
+ 0x0407fffffff70102,
+ 0x001fb400fda007ed,
+ 0x38000000b1470103,
+ 0x366603800027030f,
+ 0x5c47020000270002,
+ 0x001fb401e1a0070d,
+ 0x3880004350010000,
+ 0x5080000000770105,
+ 0x365a03807ff70306,
+ 0x001fb400fda007ed,
+ 0x5c47000000670202,
+ 0x5b6a03800ff70207,
+ 0xe24000000400000f,
+ 0x003fb400fda007ed,
+ 0x0408000000070101,
+ 0x5c9807800ff70000,
+ 0x5c47020000570101,
+ 0x001fbc00fde007ed,
+ 0xe32000000007000f,
+ 0x50b0000000070f00,
+ 0x50b0000000070f00,
+/* 0x0620: rsq_norm */
+ 0x0060b400e5a007ed,
+ 0x5c9807800ff70004,
+ 0x38a8003f00070b08,
+ 0x5c80000000870002,
+ 0x003c3401e1a01f0d,
+ 0x5c80000000470200,
+ 0x5b71040000470006,
+ 0x5b70020000670404,
+ 0x003c3401e1a00f0d,
+ 0x5c80000000470200,
+ 0x5b71040000470006,
+ 0x5b70020000670404,
+ 0x003c3401e1a00f0d,
+ 0x5c80000000470200,
+ 0x5b71040000470006,
+ 0x5b70020000670404,
+ 0x003c3401e1a00f0d,
+ 0x5c80000000470200,
+ 0x5b71040000470006,
+ 0x5b70020000670404,
+ 0x001fb401fda00f0d,
+ 0x38800041a0010404,
+ 0x5c98078000570001,
+ 0x5c98078000470000,
+ 0x001fbc00fde007ed,
0xe32000000007000f,
0x50b0000000070f00,
0x50b0000000070f00,
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
index d5318f179f2..a50e56436ba 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
@@ -127,7 +127,7 @@ NVC0LegalizeSSA::handleRCPRSQ(Instruction *i)
bld.mkSplit(src, 4, i->getSrc(0));
int chip = prog->getTarget()->getChipset();
- if (chip >= NVISA_GK104_CHIPSET && (i->op == OP_RCP || chip < NVISA_GM107_CHIPSET)) {
+ if (chip >= NVISA_GK104_CHIPSET) {
handleRCPRSQLib(i, src);
return;
}
--
2.17.1
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