nir/opt_algebraic: Convert a + b + a to b + 2a

This allows fusing into one FMA later.

Reviewed-by: Georg Lehmann <dadschoorse@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37113>

src/amd/ci/traces-amd.yml

@@ -38,7 +38,7 @@ traces:
       checksum: 6cb8190a2ee4c335291914fbc70a8bb8
   gputest/furmark-v2.trace:
     gl-radeonsi-stoney:
-      checksum: d9452b1aa606d61a51a80fb4644b7303
+      checksum: 1b0894a0059e5cdb6aadb24a7d291e9f
   gputest/triangle-v2.trace:
     gl-radeonsi-stoney:
       checksum: 2d0527e7288a0fc31099404546dadbfb

src/compiler/nir/nir_opt_algebraic.py

@@ -243,6 +243,7 @@ optimizations = [
    (('~fadd', a, ('fadd', ('fneg', a), b)), b),
    (('fadd', ('fsat', a), ('fsat', ('fneg', a))), ('fsat', ('fabs', a))),
    (('fadd', a, a), ('fmul', a, 2.0)),
+   (('fadd(contract)', a, ('fadd(is_used_once)', a, b)), ('fadd', b, ('fmul', a, 2.0))),
    (('~fmul', a, 0.0), 0.0),
    # The only effect a*0.0 should have is when 'a' is infinity, -0.0 or NaN
    (('fmul(nsz,nnan)', 'a', 0.0), 0.0),

src/freedreno/ci/traces-freedreno.yml

@@ -190,9 +190,9 @@ traces:
     freedreno-a530:
       checksum: 88188447495b819e5814368486deb0a0
     freedreno-a618:
-      checksum: eb810bd258c06f873a2d9718c5209c6d
+      checksum: 709d72f86faa9b768495888b49cad086
     zink-a618:
-      checksum: eefcef0b1167c1140c298f3908c31195
+      checksum: ac00716889f247788292e838139bc2ac
 
 # gimark requires an environment var to work around a bug, disable for now
 #  gputest/gimark-v2.trace:

src/gallium/drivers/virgl/ci/traces-virgl.yml

@@ -9,7 +9,7 @@ traces:
       checksum: f8eba0fec6e3e0af9cb09844bc73bdc8
   gputest/furmark-v2.trace:
     gl-virgl:
-      checksum: e9013d2861ac60b5b80d759455a6f058
+      checksum: 95b55f29d9f6dceb842386ea887861d4
   gputest/triangle-v2.trace:
     gl-virgl:
       checksum: 7812de00011a3a059892e36cea19c696

src/gallium/drivers/zink/ci/traces-zink.yml

@@ -67,13 +67,13 @@ traces:
   gputest/furmark-v2.trace:
     gl-zink-anv-adl:
       label: [no-perf]
-      checksum: 30649dc37efcf5dadc7b761769de51d7
+      checksum: 2d3f45cda72a1f8a54fd115fb27ee8d6
     gl-zink-anv-tgl:
-      checksum: 30649dc37efcf5dadc7b761769de51d7
+      checksum: 2d3f45cda72a1f8a54fd115fb27ee8d6
     zink-radv-vangogh:
-      checksum: d02c3021f720ae4b1023fc298f125581
+      checksum: 6466543da6b14d7e35630c6ed3e90e5f
     zink-radv-gfx1201:
-      checksum: d02c3021f720ae4b1023fc298f125581
+      checksum: 6466543da6b14d7e35630c6ed3e90e5f
 
   gputest/triangle-v2.trace:
     gl-zink-anv-adl:

src/intel/ci/traces-iris.yml

@@ -97,13 +97,13 @@ traces:
       checksum: 448886e3b24f6408e013ea13f7c96d28
   gputest/furmark-v2.trace:
     gl-intel-apl:
-      checksum: 06f4222f7f5737f93ed1d191cbdc0798
+      checksum: 54305eb5dd7fea9e34bd61567bbd4c08
     gl-intel-glk:
-      checksum: 06f4222f7f5737f93ed1d191cbdc0798
+      checksum: 54305eb5dd7fea9e34bd61567bbd4c08
     gl-intel-amly:
       checksum: 06f4222f7f5737f93ed1d191cbdc0798
     gl-intel-kbl:
-      checksum: 06f4222f7f5737f93ed1d191cbdc0798
+      checksum: 54305eb5dd7fea9e34bd61567bbd4c08
     gl-intel-whl:
       checksum: 06d587a2b934295da6ad874b750b9c9d
     gl-intel-cml: