SERVER-61929 Add basic riscv64 support

4 files changed, 14 insertions, 18 deletions

diff --git a/SConstruct b/SConstruct
index 425d1a79938..03dfdff4b91 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1350,26 +1350,17 @@ endian = get_option( "endian" )
 if endian == "auto":
     endian = sys.byteorder
 
-# These preprocessor macros came from
-# http://nadeausoftware.com/articles/2012/02/c_c_tip_how_detect_processor_type_using_compiler_predefined_macros
-#
-# NOTE: Remember to add a trailing comma to form any required one
-# element tuples, or your configure checks will fail in strange ways.
 processor_macros = {
-    'arm'        : { 'endian': 'little', 'defines': ('__arm__',) },
-    'aarch64'    : { 'endian': 'little', 'defines': ('__arm64__', '__aarch64__')},
-    'i386'       : { 'endian': 'little', 'defines': ('__i386', '_M_IX86')},
-    'ppc64le'    : { 'endian': 'little', 'defines': ('__powerpc64__',)},
-    's390x'      : { 'endian': 'big',    'defines': ('__s390x__',)},
-    'sparc'      : { 'endian': 'big',    'defines': ('__sparc',)},
-    'x86_64'     : { 'endian': 'little', 'defines': ('__x86_64', '_M_AMD64')},
-    'emscripten' : { 'endian': 'little', 'defines': ('__EMSCRIPTEN__', )},
+    'aarch64'    : { 'endian': 'little', 'check': '(defined(__arm64__) || defined(__aarch64__))' },
+    'emscripten' : { 'endian': 'little', 'check': '(defined(__EMSCRIPTEN__))' },
+    'ppc64le'    : { 'endian': 'little', 'check': '(defined(__powerpc64__))' },
+    'riscv64'    : { 'endian': 'little', 'check': '(defined(__riscv)) && (__riscv_xlen == 64)' },
+    's390x'      : { 'endian': 'big',    'check': '(defined(__s390x__))' },
+    'x86_64'     : { 'endian': 'little', 'check': '(defined(__x86_64) || defined(_M_AMD64))' },
 }
 
 def CheckForProcessor(context, which_arch):
     def run_compile_check(arch):
-        full_macros = " || ".join([ "defined(%s)" % (v) for v in processor_macros[arch]['defines']])
-
         if not endian == processor_macros[arch]['endian']:
             return False
 
@@ -1379,7 +1370,7 @@ def CheckForProcessor(context, which_arch):
         #else
         #error not {1}
         #endif
-        """.format(full_macros, arch)
+        """.format(processor_macros[arch]['check'], arch)
 
         return context.TryCompile(textwrap.dedent(test_body), ".c")
 
diff --git a/src/mongo/platform/atomic_word.h b/src/mongo/platform/atomic_word.h
index 1f3f0a83892..c277497b15c 100644
--- a/src/mongo/platform/atomic_word.h
+++ b/src/mongo/platform/atomic_word.h
@@ -125,8 +125,12 @@ public:
     }
 
 protected:
+    // At least with GCC 10, this assertion fails for small types like bool.
+#if !defined(__riscv)
     MONGO_STATIC_ASSERT(std::atomic<WordType>::is_always_lock_free);  // NOLINT
-    std::atomic<WordType> _value;                                     // NOLINT
+#endif
+
+    std::atomic<WordType> _value;  // NOLINT
 };
 
 /**
diff --git a/src/third_party/IntelRDFPMathLib20U1/SConscript b/src/third_party/IntelRDFPMathLib20U1/SConscript
index b53c1f7762c..6fc8163484a 100644
--- a/src/third_party/IntelRDFPMathLib20U1/SConscript
+++ b/src/third_party/IntelRDFPMathLib20U1/SConscript
@@ -313,7 +313,7 @@ elif processor == "aarch64":
     cpp_defines['efi2'] = '1'
     cpp_defines['EFI2'] = '1'
 # Using 64 bit little endian
-elif processor == 'x86_64' or processor == 'ppc64le':
+elif processor == 'x86_64' or processor == 'ppc64le' or processor == 'riscv64':
     cpp_defines['efi2'] = '1'
     cpp_defines['EFI2'] = '1'
 # Using 64 bit big endian
diff --git a/src/third_party/wiredtiger/SConscript b/src/third_party/wiredtiger/SConscript
index b7f50e9ff62..084b8281bc3 100644
--- a/src/third_party/wiredtiger/SConscript
+++ b/src/third_party/wiredtiger/SConscript
@@ -154,6 +154,7 @@ condition_map = {
 
     'ARM64_HOST'   : env['TARGET_ARCH'] == 'aarch64',
     'POWERPC_HOST' : env['TARGET_ARCH'] == 'ppc64le',
+    'RISCV64_HOST' : env['TARGET_ARCH'] == 'riscv64',
     'X86_HOST'     : env['TARGET_ARCH'] == 'x86_64',
     'ZSERIES_HOST' : env['TARGET_ARCH'] == 's390x',
 }