LoongArch processors may not support memory accesses without natural
alignments. Building libraries with -mstrict-align may help with
toolchain binary compatiblity and performance on these implementations
(e.g. Loongson 2K1000LA).
With this patch, no significant performance degredation is observed on
current mainstream LoongArch processors.
gcc/ChangeLog:
* gcc/config/t-linux: add -mstrict-align via self_specs
when building GCC libraries.
---
gcc/config/loongarch/t-linux | 3 +++
1 file changed, 3 insertions(+)
diff --git a/gcc/config/loongarch/t-linux b/gcc/config/loongarch/t-linux
index 75bb430c555..2a170d600a9 100644
--- a/gcc/config/loongarch/t-linux
+++ b/gcc/config/loongarch/t-linux
@@ -35,6 +35,9 @@ gen_mlib_spec = $(if $(word 2,$1),\
# clean up the result of DRIVER_SELF_SPEC to avoid conflict
lib_build_self_spec = %<march=* %<mtune=* %<mcmodel=* %<mfpu=* %<msimd=*
+# build libraries with -mstrict-align by default
+lib_build_self_spec += -mstrict-align
+
# append user-specified build options from --with-multilib-list
lib_build_self_spec += $(foreach mlib,$(subst $(comma),
,$(TM_MULTILIB_CONFIG)),\
$(call gen_mlib_spec,$(subst /, ,$(mlib))))
--
2.41.0
