On Fri, 5 Sep 2025 06:16:01 GMT, SendaoYan <s...@openjdk.org> wrote: >> Hi all, >> >> Build jdk on linux-aarch64 with older assembler version(as 2.30) will report >> compilation failre, shows as >> [JDK-8366777](https://bugs.openjdk.org/browse/JDK-8366777). >> >> This PR add the expression `svfloat64_t a() {}` to makefile which will >> trigger the compilation during configure stage. After this PR, at configure >> stage will check the gcc and assember support `-march=armv8-a+sve` or not >> more comprehensive. >> >> Testing: >> - [x] On linux-aarch64 gcc12.3.1 as2.37, configure set SVE_CFLAGS as >> '-march=armv8-a+sve' >> - [x] On linux-aarch64 gcc10.3.0 as2.30, configure set SVE_CFLAGS as empty >> >> >> The compilation fails demo as below: >> >> >> # cat sve.c >> #include <arm_sve.h> >> svfloat64_t a() {} >> # gcc -march=armv8-a+sve sve.c >> /tmp/ccVOzMzb.s: Assembler messages: >> /tmp/ccVOzMzb.s:6: Error: unknown pseudo-op: `.variant_pcs' > > SendaoYan has updated the pull request incrementally with one additional > commit since the last revision: > > Use UTIL_ARG_ENABLE instead of AC_ARG_ENABLE
make/autoconf/flags-cflags.m4 line 950: > 948: # check the compiler and binutils support sve or not > 949: AC_MSG_CHECKING([if Arm SVE ACLE is supported]) > 950: AC_COMPILE_IFELSE([AC_LANG_PROGRAM( Now that I started looking closer at this, I realize that we are inside a macro that gets called for both the BUILD and TARGET compiler (note the $2 prefix on several variables). For a call to `AC_COMPILER_IFELSE` to work correctly in that context, you need to temporarily change `CC` and `CFLAGS` to the correct compiler and flags setup. See the definition of `FLAGS_C_COMPILER_CHECK_ARGUMENTS` in flags.m4 to see how that is done. make/autoconf/flags-cflags.m4 line 981: > 979: if test "x$$2SVE_CFLAGS" != "x" && test "x$DEBUG_LEVEL" != > xrelease && test "x$TOOLCHAIN_TYPE" = xgcc ; then > 980: INIT_ZERO_FLAG="-ftrivial-auto-var-init=zero" > 981: FLAGS_COMPILER_CHECK_ARGUMENTS(ARGUMENT: [$INIT_ZERO_FLAG], When calling `FLAGS_COMPILER_CHECK_ARGUMENTS` you from this context, you need to include the `PREFIX` argument. See examples further up in this file. make/autoconf/flags-cflags.m4 line 996: > 994: AC_DEFUN([BPERF_SETUP_SVE], > 995: [ > 996: UTIL_ARG_ENABLE(NAME: aarch64-sve, DEFAULT: auto, The idea with this macro is that you put the supported check and actions on enabled/disabled in the call and let it handle the logic. It shouldn't be moved to a separate macro. Also, macros defined in this file should have the `FLAGS` prefix, not `BPERF`. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/27073#discussion_r2325028873 PR Review Comment: https://git.openjdk.org/jdk/pull/27073#discussion_r2325031564 PR Review Comment: https://git.openjdk.org/jdk/pull/27073#discussion_r2325022758
