nir/algebraic: optimize some code generated by nir_lower_bit_size

fossil-db (Navi):
Totals from 193 (28.26% of 683) affected shaders:
SGPRs: 8680 -> 8848 (+1.94%)
SpillVGPRs: 1165 -> 1189 (+2.06%)
CodeSize: 1072588 -> 1058232 (-1.34%)
Instrs: 188630 -> 185726 (-1.54%)

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
67 jobs for !4379 with nir_lower_bit_size
latest detached
Status Job ID Name Coverage
  Container+Docs
manual #3858576
aarch64 manual
arm_build
manual #3858577
manual
arm_test-base
manual #3858573
manual
x86_build-base
manual #3858575
manual
x86_build_old
manual #3858574
manual
x86_test-base
 
  Container 2
created #3858586
arm64_test
created #3858581
i386_build
created #3858578
aarch64
kernel+rootfs_arm64
created #3858579
aarch64
kernel+rootfs_armhf
created #3858582
ppc64el_build
created #3858583
s390x_build
created #3858580
x86_build
created #3858584
x86_test-gl
created #3858585
x86_test-vk
 
  Meson X86 64
created #3858590
meson-clang
created #3858589
meson-classic
created #3858591
meson-clover
created #3858592
meson-clover-old-llvm
created #3858588
meson-gallium
created #3858587
meson-testing
created #3858593
meson-vulkan
 
  Scons
created #3858594
allowed to fail
scons-win64
 
  Meson Misc
created #3858596
aarch64
meson-arm64
created #3858597
aarch64
meson-arm64-build-test
created #3858595
aarch64
meson-armhf
created #3858598
meson-i386
created #3858601
meson-mingw32-x86_64
created #3858600
kvm
meson-ppc64el
created #3858599
kvm
meson-s390x
 
  Llvmpipe
created #3858605
llvmpipe-gles2
created #3858606
llvmpipe-traces
created #3858603
piglit-glslparser
created #3858602
piglit-quick_gl
created #3858604
piglit-quick_shader
 
  Softpipe
created #3858607
softpipe-gles2
created #3858610
softpipe-gles31 1/4
created #3858608
softpipe-gles3 1/2
created #3858611
softpipe-gles31 2/4
created #3858612
softpipe-gles31 3/4
created #3858613
softpipe-gles31 4/4
created #3858609
softpipe-gles3 2/2
 
  Freedreno
created #3858618
google-freedreno-db410c
arm64_a306_gles2
created #3858619
google-freedreno-db410c
arm64_a306_gles3
created #3858620
google-freedreno-db410c
arm64_a306_gles3_options
created #3858621
google-freedreno-db820c
arm64_a530_gles2
created #3858622
google-freedreno-db820c
arm64_a530_gles3
created #3858623
google-freedreno-db820c
arm64_a530_gles31
created #3858614
google-freedreno-cheza
arm64_a630_gles2
created #3858616
google-freedreno-cheza
arm64_a630_gles3
created #3858615
google-freedreno-cheza
arm64_a630_gles31
created #3858617
google-freedreno-cheza
arm64_a630_vk
 
  Panfrost
created #3858624
mesa-ci-aarch64-lava-collabora
panfrost-t720-gles2:arm64
created #3858625
mesa-ci-aarch64-lava-collabora
panfrost-t760-gles2:armhf
created #3858626
mesa-ci-aarch64-lava-collabora
panfrost-t860-gles2:arm64
created #3858627
mesa-ci-aarch64-lava-collabora
panfrost-t860-gles3:arm64
 
  Radv
created #3858628
radv-fossils
 
  Virgl
created #3858636
virgl-gl30-on-gl
created #3858637
virgl-gl31-on-gl
created #3858638
virgl-gl32-on-gl
created #3858629
virgl-gles2-on-gl
created #3858632
virgl-gles31-on-gl 1/4
created #3858633
virgl-gles31-on-gl 2/4
created #3858634
virgl-gles31-on-gl 3/4
created #3858635
virgl-gles31-on-gl 4/4
created #3858630
virgl-gles3-on-gl 1/2
created #3858631
virgl-gles3-on-gl 2/2
created #3858639
virgl-traces