Author: lenary Date: Fri Jun 21 03:03:31 2019 New Revision: 364018 URL: http://llvm.org/viewvc/llvm-project?rev=364018&view=rev Log: [RISC-V] Add -msave-restore and -mno-save-restore to clang driver
Summary: The GCC RISC-V toolchain accepts `-msave-restore` and `-mno-save-restore` to control whether libcalls are used for saving and restoring the stack within prologues and epilogues. Clang currently errors if someone passes -msave-restore or -mno-save-restore. This means that people need to change build configurations to use clang. This patch adds these flags, so that clang invocations can now match gcc. As the RISC-V backend does not currently have a `save-restore` target feature, we emit a warning if someone requests `-msave-restore`. LLVM does not error if we pass the (unimplemented) target features `+save-restore` or `-save-restore`. Reviewers: asb, luismarques Reviewed By: asb Subscribers: rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D63498 Modified: cfe/trunk/include/clang/Driver/Options.td cfe/trunk/lib/Driver/ToolChains/Arch/RISCV.cpp cfe/trunk/test/Driver/riscv-features.c Modified: cfe/trunk/include/clang/Driver/Options.td URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/Options.td?rev=364018&r1=364017&r2=364018&view=diff ============================================================================== --- cfe/trunk/include/clang/Driver/Options.td (original) +++ cfe/trunk/include/clang/Driver/Options.td Fri Jun 21 03:03:31 2019 @@ -2130,6 +2130,10 @@ def mrelax : Flag<["-"], "mrelax">, Grou HelpText<"Enable linker relaxation">; def mno_relax : Flag<["-"], "mno-relax">, Group<m_riscv_Features_Group>, HelpText<"Disable linker relaxation">; +def msave_restore : Flag<["-"], "msave-restore">, Group<m_riscv_Features_Group>, + HelpText<"Enable using library calls for save and restore">; +def mno_save_restore : Flag<["-"], "mno-save-restore">, Group<m_riscv_Features_Group>, + HelpText<"Disable using library calls for save and restore">; def munaligned_access : Flag<["-"], "munaligned-access">, Group<m_arm_Features_Group>, HelpText<"Allow memory accesses to be unaligned (AArch32/AArch64 only)">; Modified: cfe/trunk/lib/Driver/ToolChains/Arch/RISCV.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/ToolChains/Arch/RISCV.cpp?rev=364018&r1=364017&r2=364018&view=diff ============================================================================== --- cfe/trunk/lib/Driver/ToolChains/Arch/RISCV.cpp (original) +++ cfe/trunk/lib/Driver/ToolChains/Arch/RISCV.cpp Fri Jun 21 03:03:31 2019 @@ -358,6 +358,16 @@ void riscv::getRISCVTargetFeatures(const else Features.push_back("-relax"); + // -mno-save-restore is default, unless -msave-restore is specified. + if (Args.hasFlag(options::OPT_msave_restore, options::OPT_mno_save_restore, false)) { + Features.push_back("+save-restore"); + // ... but we don't yet support +save-restore, so issue a warning. + D.Diag(diag::warn_drv_clang_unsupported) + << Args.getLastArg(options::OPT_msave_restore)->getAsString(Args); + } else { + Features.push_back("-save-restore"); + } + // Now add any that the user explicitly requested on the command line, // which may override the defaults. handleTargetFeaturesGroup(Args, Features, options::OPT_m_riscv_Features_Group); Modified: cfe/trunk/test/Driver/riscv-features.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/riscv-features.c?rev=364018&r1=364017&r2=364018&view=diff ============================================================================== --- cfe/trunk/test/Driver/riscv-features.c (original) +++ cfe/trunk/test/Driver/riscv-features.c Fri Jun 21 03:03:31 2019 @@ -3,11 +3,23 @@ // CHECK: fno-signed-char +// RUN: %clang -target riscv32-unknown-elf -### %s 2>&1 | FileCheck %s -check-prefix=DEFAULT + // RUN: %clang -target riscv32-unknown-elf -### %s -mrelax 2>&1 | FileCheck %s -check-prefix=RELAX // RUN: %clang -target riscv32-unknown-elf -### %s -mno-relax 2>&1 | FileCheck %s -check-prefix=NO-RELAX -// RUN: %clang -target riscv32-unknown-elf -### %s 2>&1 | FileCheck %s -check-prefix=DEFAULT // RELAX: "-target-feature" "+relax" // NO-RELAX: "-target-feature" "-relax" // DEFAULT: "-target-feature" "+relax" // DEFAULT-NOT: "-target-feature" "-relax" + +// RUN: %clang -target riscv32-unknown-elf -### %s -msave-restore 2>&1 | FileCheck %s -check-prefix=SAVE-RESTORE +// RUN: %clang -target riscv32-unknown-elf -### %s -mno-save-restore 2>&1 | FileCheck %s -check-prefix=NO-SAVE-RESTORE + +// SAVE-RESTORE: warning: the clang compiler does not support '-msave-restore' +// DEFAULT-NOT: warning: the clang compiler does not support + +// SAVE-RESTORE: "-target-feature" "+save-restore" +// NO-SAVE-RESTORE: "-target-feature" "-save-restore" +// DEFAULT: "-target-feature" "-save-restore" +// DEFAULT-NOT: "-target-feature" "+save-restore" \ No newline at end of file _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
