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