intel/fs: Don't count integer instructions as being possibly coissue

Integer instructions don't coissue.  Before e64be391dd0
("intel/compiler: generalize the combine constants pass"), this pass
only looked at float sources.  There's no shader-db data in that commit,
so I collected some.  The results are not good:

    Haswell
    total instructions in shared programs: 11898805 -> 11908127 (0.08%)
    instructions in affected programs: 1218680 -> 1228002 (0.76%)
    helped: 2
    HURT: 5171
    helped stats (abs) min: 12 max: 111 x̄: 61.50 x̃: 61
    helped stats (rel) min: 1.59% max: 9.20% x̄: 5.40% x̃: 5.40%
    HURT stats (abs)   min: 1 max: 311 x̄: 1.83 x̃: 1
    HURT stats (rel)   min: 0.02% max: 9.91% x̄: 1.05% x̃: 0.70%
    95% mean confidence interval for instructions value: 1.55 2.05
    95% mean confidence interval for instructions %-change: 1.02% 1.08%
    Instructions are HURT.

    total cycles in shared programs: 221664974 -> 221404750 (-0.12%)
    cycles in affected programs: 120012620 -> 119752396 (-0.22%)
    helped: 3464
    HURT: 3159
    helped stats (abs) min: 1 max: 428160 x̄: 314.55 x̃: 16
    helped stats (rel) min: <.01% max: 57.33% x̄: 3.40% x̃: 1.28%
    HURT stats (abs)   min: 1 max: 87846 x̄: 262.54 x̃: 14
    HURT stats (rel)   min: <.01% max: 85.57% x̄: 3.01% x̃: 0.77%
    95% mean confidence interval for cycles value: -224.23 145.65
    95% mean confidence interval for cycles %-change: -0.50% -0.19%
    Inconclusive result (value mean confidence interval includes 0).

    total spills in shared programs: 9804 -> 10047 (2.48%)
    spills in affected programs: 6869 -> 7112 (3.54%)
    helped: 2
    HURT: 41

    total fills in shared programs: 19863 -> 20319 (2.30%)
    fills in affected programs: 17428 -> 17884 (2.62%)
    helped: 2
    HURT: 41

    LOST:   20
    GAINED: 13

This also prevents regressions in "intel/fs: Promote integer constants
after lowering integer multiplication" (note: that patch will probably
not be committed).  When the passes are reorderd, code like

    mul(8)      acc0<1>D    g9<8,8,1>D  -2078209981D    { align1 1Q };

gets turned into

    mov(1)      g23<1>D     2078209981D                 { align1 WE_all 1N };
    ...
    mul(8)      acc0<1>D    g13<8,8,1>D  -g23<0,1,0>D   { align1 1Q compacted };

It's not 100% clear why, but these produce different results.  Note that
-2078209981 & 0x0ffff = 0x0843, and -(2078209981 & 0x0ffff) =
0xffff0843.  It seems like the upper 16-bits of the negation should be
ignored.

Fixes: e64be391dd0 ("intel/compiler: generalize the combine constants pass")
Cc: Iago Toral Quiroga <itoral@igalia.com>
Suggested-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>

The shaders with spills or fills hurt are the usual suspects.  A couple
compute shaders in Dirt Showdown and a compute shader in Bioshock
Infinite.  On Haswell, a compute shader (that appears twice in
shader-db) from Aztec Ruins was also hurt for spill and fills.

Haswell
total instructions in shared programs: 11573934 -> 11568335 (-0.05%)
instructions in affected programs: 828623 -> 823024 (-0.68%)
helped: 2825
HURT: 6
helped stats (abs) min: 1 max: 134 x̄: 2.16 x̃: 1
helped stats (rel) min: 0.02% max: 9.05% x̄: 0.84% x̃: 0.61%
HURT stats (abs)   min: 1 max: 216 x̄: 81.83 x̃: 56
HURT stats (rel)   min: 0.16% max: 8.65% x̄: 4.21% x̃: 4.68%
95% mean confidence interval for instructions value: -2.31 -1.64
95% mean confidence interval for instructions %-change: -0.85% -0.80%
Instructions are helped.

total cycles in shared programs: 187573593 -> 187004633 (-0.30%)
cycles in affected programs: 82816107 -> 82247147 (-0.69%)
helped: 2186
HURT: 1741
helped stats (abs) min: 1 max: 35230 x̄: 326.96 x̃: 16
helped stats (rel) min: <.01% max: 46.11% x̄: 3.11% x̃: 0.90%
HURT stats (abs)   min: 1 max: 6138 x̄: 83.73 x̃: 16
HURT stats (rel)   min: <.01% max: 104.11% x̄: 2.73% x̃: 0.75%
95% mean confidence interval for cycles value: -197.13 -92.64
95% mean confidence interval for cycles %-change: -0.72% -0.33%
Cycles are helped.

total spills in shared programs: 7870 -> 7743 (-1.61%)
spills in affected programs: 2260 -> 2133 (-5.62%)
helped: 31
HURT: 5

total fills in shared programs: 6320 -> 6263 (-0.90%)
fills in affected programs: 3547 -> 3490 (-1.61%)
helped: 31
HURT: 6

LOST:   9
GAINED: 9

Ivybridge
total instructions in shared programs: 11863372 -> 11859793 (-0.03%)
instructions in affected programs: 757183 -> 753604 (-0.47%)
helped: 2236
HURT: 3
helped stats (abs) min: 1 max: 81 x̄: 1.86 x̃: 1
helped stats (rel) min: 0.03% max: 5.26% x̄: 0.74% x̃: 0.48%
HURT stats (abs)   min: 11 max: 301 x̄: 192.33 x̃: 265
HURT stats (rel)   min: 1.55% max: 10.51% x̄: 6.89% x̃: 8.62%
95% mean confidence interval for instructions value: -2.01 -1.18
95% mean confidence interval for instructions %-change: -0.77% -0.70%
Instructions are helped.

total cycles in shared programs: 178377378 -> 177946087 (-0.24%)
cycles in affected programs: 76261390 -> 75830099 (-0.57%)
helped: 1635
HURT: 1395
helped stats (abs) min: 1 max: 34796 x̄: 333.53 x̃: 16
helped stats (rel) min: <.01% max: 47.15% x̄: 2.82% x̃: 0.64%
HURT stats (abs)   min: 1 max: 4315 x̄: 81.74 x̃: 18
HURT stats (rel)   min: <.01% max: 49.98% x̄: 1.99% x̃: 0.53%
95% mean confidence interval for cycles value: -197.06 -87.62
95% mean confidence interval for cycles %-change: -0.78% -0.43%
Cycles are helped.

total spills in shared programs: 4188 -> 4182 (-0.14%)
spills in affected programs: 1557 -> 1551 (-0.39%)
helped: 30
HURT: 3

total fills in shared programs: 5056 -> 5245 (3.74%)
fills in affected programs: 2708 -> 2897 (6.98%)
helped: 30
HURT: 3

LOST:   5
GAINED: 1

No shader-db changes on any other Intel platform.

Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3544>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3544>

1 files changed, 8 insertions, 1 deletions

diff --git a/src/intel/compiler/brw_fs_combine_constants.cpp b/src/intel/compiler/brw_fs_combine_constants.cpp
index 2a28351beef..d10ac0219cf 100644
--- a/src/intel/compiler/brw_fs_combine_constants.cpp
+++ b/src/intel/compiler/brw_fs_combine_constants.cpp
@@ -56,7 +56,14 @@ could_coissue(const struct gen_device_info *devinfo, const fs_inst *inst)
    case BRW_OPCODE_CMP:
    case BRW_OPCODE_ADD:
    case BRW_OPCODE_MUL:
-      return true;
+      /* Only float instructions can coissue.  We don't have a great
+       * understanding of whether or not something like float(int(a) + int(b))
+       * would be considered float (based on the destination type) or integer
+       * (based on the source types), so we take the conservative choice of
+       * only promoting when both destination and source are float.
+       */
+      return inst->dst.type == BRW_REGISTER_TYPE_F &&
+             inst->src[0].type == BRW_REGISTER_TYPE_F;
    default:
       return false;
    }