ci: enable IPO/LTO only for nightly builds

1. nightly takes a long, the extra few minutes for linking don't matter
2. nightly will run faster, since where it's CPU dependent it's at least +5% perf
3. it may reveal some painful areas of common code or driver.
4. for some jobs (not enabled yet, it generates ugly errors, disable
   there

Signed-off-by: David Heidelberg <david.heidelberg@collabora.com>
Signed-off-by: David Heidelberg <david@ixit.cz>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28684>

.gitlab-ci/build/gitlab-ci.yml

@@ -340,7 +340,6 @@ fedora-release:
       -D glvnd=enabled
       -D platforms=x11,wayland
     EXTRA_OPTION: >
-      -D b_lto=true
       -D osmesa=true
       -D selinux=true
       -D tools=drm-shim,etnaviv,freedreno,glsl,intel,nir,nouveau,lima,panfrost,imagination

.gitlab-ci/meson/build.sh

@@ -98,6 +98,31 @@ case $CI_JOB_NAME in
         ;;
 esac
 
+# LTO handling
+case $CI_PIPELINE_SOURCE in
+    schedule)
+      # run builds with LTO only for nightly
+      if [ "$CI_JOB_NAME" == "debian-ppc64el" ]; then
+	      # /tmp/ccWlDCPV.s: Assembler messages:
+	      # /tmp/ccWlDCPV.s:15250880: Error: operand out of range (0xfffffffffdd4e688 is not between 0xfffffffffe000000 and 0x1fffffc)
+	      LTO=false
+      # enable one by one for now
+      elif [ "$CI_JOB_NAME" == "fedora-release" || "$CI_JOB_NAME" == "debian-build-testing" ]; then
+	      LTO=true
+      else
+	      LTO=false
+      fi
+      ;;
+    *)
+      # run Fedora with LTO in pre-merge for now
+      if [ "$CI_JOB_NAME" == "fedora-release" ]; then
+	      LTO=true
+      else
+	      LTO=false
+      fi
+      ;;
+esac
+
 section_switch meson-configure "meson: configure"
 
 rm -rf _build
@@ -123,6 +148,7 @@ meson setup _build \
       -D vulkan-drivers=${VULKAN_DRIVERS:-[]} \
       -D video-codecs=all \
       -D werror=true \
+      -D b_lto=${LTO} \
       ${EXTRA_OPTION}
 cd _build
 meson configure