Hi Thomas,
On 18 November 2016 at 17:51, Thomas Preudhomme <thomas.preudho...@foss.arm.com> wrote: > On 11/11/16 14:35, Kyrill Tkachov wrote: >> >> >> On 08/11/16 13:36, Thomas Preudhomme wrote: >>> >>> Ping? >>> >>> Best regards, >>> >>> Thomas >>> >>> On 25/10/16 18:07, Thomas Preudhomme wrote: >>>> >>>> Hi, >>>> >>>> Currently when a user compiles for a thumb-only target (such as Cortex-M >>>> processors) without specifying the -mthumb option GCC throws the error >>>> "target >>>> CPU does not support ARM mode". This is suboptimal from a usability >>>> point of >>>> view: the -mthumb could be deduced from the -march or -mcpu option when >>>> there is >>>> no ambiguity. >>>> >>>> This patch implements this behavior by extending the DRIVER_SELF_SPECS >>>> to >>>> automatically append -mthumb to the command line for thumb-only targets. >>>> It does >>>> so by checking the last -march option if any is given or the last -mcpu >>>> option >>>> otherwise. There is no ordering issue because conflicting -mcpu and >>>> -march is >>>> already handled. >>>> >>>> Note that the logic cannot be implemented in function >>>> arm_option_override >>>> because we need to provide the modified command line to the GCC driver >>>> for >>>> finding the right multilib path and the function arm_option_override is >>>> executed >>>> too late for that effect. >>>> >>>> ChangeLog entries are as follow: >>>> >>>> *** gcc/ChangeLog *** >>>> >>>> 2016-10-18 Terry Guo <terry....@arm.com> >>>> Thomas Preud'homme <thomas.preudho...@arm.com> >>>> >>>> PR target/64802 >>>> * common/config/arm/arm-common.c (arm_target_thumb_only): New >>>> function. >>>> * config/arm/arm-opts.h: Include arm-flags.h. >>>> (struct arm_arch_core_flag): Define. >>>> (arm_arch_core_flags): Define. >>>> * config/arm/arm-protos.h: Include arm-flags.h. >>>> (FL_NONE, FL_ANY, FL_CO_PROC, FL_ARCH3M, FL_MODE26, FL_MODE32, >>>> FL_ARCH4, FL_ARCH5, FL_THUMB, FL_LDSCHED, FL_STRONG, FL_ARCH5E, >>>> FL_XSCALE, FL_ARCH6, FL_VFPV2, FL_WBUF, FL_ARCH6K, FL_THUMB2, >>>> FL_NOTM, >>>> FL_THUMB_DIV, FL_VFPV3, FL_NEON, FL_ARCH7EM, FL_ARCH7, >>>> FL_ARM_DIV, >>>> FL_ARCH8, FL_CRC32, FL_SMALLMUL, FL_NO_VOLATILE_CE, FL_IWMMXT, >>>> FL_IWMMXT2, FL_ARCH6KZ, FL2_ARCH8_1, FL2_ARCH8_2, FL2_FP16INST, >>>> FL_TUNE, FL_FOR_ARCH2, FL_FOR_ARCH3, FL_FOR_ARCH3M, >>>> FL_FOR_ARCH4, >>>> FL_FOR_ARCH4T, FL_FOR_ARCH5, FL_FOR_ARCH5T, FL_FOR_ARCH5E, >>>> FL_FOR_ARCH5TE, FL_FOR_ARCH5TEJ, FL_FOR_ARCH6, FL_FOR_ARCH6J, >>>> FL_FOR_ARCH6K, FL_FOR_ARCH6Z, FL_FOR_ARCH6ZK, FL_FOR_ARCH6KZ, >>>> FL_FOR_ARCH6T2, FL_FOR_ARCH6M, FL_FOR_ARCH7, FL_FOR_ARCH7A, >>>> FL_FOR_ARCH7VE, FL_FOR_ARCH7R, FL_FOR_ARCH7M, FL_FOR_ARCH7EM, >>>> FL_FOR_ARCH8A, FL2_FOR_ARCH8_1A, FL2_FOR_ARCH8_2A, >>>> FL_FOR_ARCH8M_BASE, >>>> FL_FOR_ARCH8M_MAIN, arm_feature_set, ARM_FSET_MAKE, >>>> ARM_FSET_MAKE_CPU1, ARM_FSET_MAKE_CPU2, ARM_FSET_CPU1, >>>> ARM_FSET_CPU2, >>>> ARM_FSET_EMPTY, ARM_FSET_ANY, ARM_FSET_HAS_CPU1, >>>> ARM_FSET_HAS_CPU2, >>>> ARM_FSET_HAS_CPU, ARM_FSET_ADD_CPU1, ARM_FSET_ADD_CPU2, >>>> ARM_FSET_DEL_CPU1, ARM_FSET_DEL_CPU2, ARM_FSET_UNION, >>>> ARM_FSET_INTER, >>>> ARM_FSET_XOR, ARM_FSET_EXCLUDE, ARM_FSET_IS_EMPTY, >>>> ARM_FSET_CPU_SUBSET): Move to ... >>>> * config/arm/arm-flags.h: This new file. >>>> * config/arm/arm.h (TARGET_MODE_SPEC_FUNCTIONS): Define. >>>> (EXTRA_SPEC_FUNCTIONS): Add TARGET_MODE_SPEC_FUNCTIONS to its >>>> value. >>>> (TARGET_MODE_SPECS): Define. >>>> (DRIVER_SELF_SPECS): Add TARGET_MODE_SPECS to its value. >>>> >>>> >>>> *** gcc/testsuite/ChangeLog *** >>>> >>>> 2016-10-11 Thomas Preud'homme <thomas.preudho...@arm.com> >>>> >>>> PR target/64802 >>>> * gcc.target/arm/optional_thumb-1.c: New test. >>>> * gcc.target/arm/optional_thumb-2.c: New test. >>>> * gcc.target/arm/optional_thumb-3.c: New test. >>>> >>>> >>>> No regression when running the testsuite for -mcpu=cortex-m0 -mthumb, >>>> -mcpu=cortex-m0 -marm and -mcpu=cortex-a8 -marm >>>> >>>> Is this ok for trunk? >>>> >> >> This looks like a useful usability improvement. >> This is ok after a bootstrap on an arm-none-linux-gnueabihf target. >> >> Sorry for the delay, >> Kyrill > > > I've rebased the patch on top of the arm_feature_set type consistency fix > [1] and committed it. The committed patch is in attachment for reference. > > [1] https://gcc.gnu.org/ml/gcc-patches/2016-11/msg01680.html > Since this commit (242597), I've noticed that: - the 2 new tests optional_thumb-1.c and optional_thumb-2.c fail if GCC was configured --with-mode=arm. The error message is: cc1: error: target CPU does not support ARM mode - on armeb --with-mode=arm, gcc.dg/vect/pr64252.c fails at execution See: http://people.linaro.org/~christophe.lyon/cross-validation/gcc/trunk/242597/report-build-info.html Christophe > Best regards, > > Thomas
