[RISCV] Add option aliases: -mcmodel=medany and -mcmodel=medlow

RISC-V GCC use -mcmodel=medany and -mcmodel=medlow, but LLVM use
-mcmodel=small and -mcmodel=medium.

Add those two option aliases for provide same user interface between
GCC and LLVM.

Reviewed By: lenary

Differential Revision: https://reviews.llvm.org/D67066

llvm-svn: 372080

Author: kito-cheng

clang/include/clang/Driver/Options.td

@@ -2177,6 +2177,12 @@ 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 mcmodel_EQ_medlow : Flag<["-"], "mcmodel=medlow">, Group<m_riscv_Features_Group>,
+  Flags<[CC1Option]>, Alias<mcmodel_EQ>, AliasArgs<["small"]>,
+  HelpText<"Equivalent to -mcmodel=small, compatible with RISC-V gcc.">;
+def mcmodel_EQ_medany : Flag<["-"], "mcmodel=medany">, Group<m_riscv_Features_Group>,
+  Flags<[CC1Option]>, Alias<mcmodel_EQ>, AliasArgs<["medium"]>,
+  HelpText<"Equivalent to -mcmodel=medium, compatible with RISC-V gcc.">;
 
 def munaligned_access : Flag<["-"], "munaligned-access">, Group<m_arm_Features_Group>,
   HelpText<"Allow memory accesses to be unaligned (AArch32/AArch64 only)">;

clang/test/Preprocessor/riscv-cmodel.c

@@ -8,6 +8,11 @@
 // RUN: %clang -target riscv64-unknown-linux-gnu -march=rv64i -x c -E -dM %s \
 // RUN: -mcmodel=small -o - | FileCheck --check-prefix=CHECK-MEDLOW %s
 
+// RUN: %clang -target riscv32-unknown-linux-gnu -march=rv32i -x c -E -dM %s \
+// RUN: -mcmodel=medlow -o - | FileCheck --check-prefix=CHECK-MEDLOW %s
+// RUN: %clang -target riscv64-unknown-linux-gnu -march=rv64i -x c -E -dM %s \
+// RUN: -mcmodel=medlow -o - | FileCheck --check-prefix=CHECK-MEDLOW %s
+
 // CHECK-MEDLOW: #define __riscv_cmodel_medlow 1
 // CHECK-MEDLOW-NOT: __riscv_cmodel_medany
 
@@ -16,5 +21,10 @@
 // RUN: %clang -target riscv64-unknown-linux-gnu -march=rv64i -x c -E -dM %s \
 // RUN: -mcmodel=medium -o - | FileCheck --check-prefix=CHECK-MEDANY %s
 
+// RUN: %clang -target riscv32-unknown-linux-gnu -march=rv32i -x c -E -dM %s \
+// RUN: -mcmodel=medany -o - | FileCheck --check-prefix=CHECK-MEDANY %s
+// RUN: %clang -target riscv64-unknown-linux-gnu -march=rv64i -x c -E -dM %s \
+// RUN: -mcmodel=medany -o - | FileCheck --check-prefix=CHECK-MEDANY %s
+
 // CHECK-MEDANY: #define __riscv_cmodel_medany 1
 // CHECK-MEDANY-NOT: __riscv_cmodel_medlow