From c8fbac45246c40a2785be1e3b7e2430ceafda091 Mon Sep 17 00:00:00 2001
From: Stewart X Addison <sxa@ibm.com>
Date: Tue, 1 Sep 2026 16:30:26 +0100
Subject: [PATCH] build: activate correct default flags for riscv64

Signed-off-by: Stewart X Addison <sxa@ibm.com>
---
 common.gypi              | 8 ++++++++
 tools/v8_gypfiles/v8.gyp | 3 +++
 2 files changed, 11 insertions(+)

diff --git a/common.gypi b/common.gypi
index a83523286a91..1729bfd3cb00 100644
--- a/common.gypi
+++ b/common.gypi
@@ -611,6 +611,10 @@
                 'cflags': [ '-m64', '-march=z14' ],
                 'ldflags': [ '-m64', '-march=z14' ],
               }],
+              [ 'host_arch=="riscv64" and OS=="linux"', {
+                'cflags': [ '-march=rv64gc' ],
+                'ldflags': [ '-march=rv64gc' ],
+              }],
             ],
           }],
           ['_toolset=="target"', {
@@ -636,6 +640,10 @@
                 'cflags': [ '-m64', '-march=z14' ],
                 'ldflags': [ '-m64', '-march=z14' ],
               }],
+              [ 'target_arch=="riscv64" and OS=="linux"', {
+                'cflags': [ '-march=rv64gc' ],
+                'ldflags': [ '-march=rv64gc' ],
+              }],
             ],
           }],
         ],
diff --git a/tools/v8_gypfiles/v8.gyp b/tools/v8_gypfiles/v8.gyp
index 32fc99e2af9f..7c7ebc8af42a 100644
--- a/tools/v8_gypfiles/v8.gyp
+++ b/tools/v8_gypfiles/v8.gyp
@@ -2485,6 +2485,9 @@
         ['v8_target_arch=="ppc64" or v8_target_arch=="s390x"', {
           'defines': ['TOOLCHAIN_MISS_ASM_HWCAP_H',],
         }],
+        ['v8_target_arch=="riscv64"', {
+          'defines': ['HWY_BROKEN_TARGETS=HWY_RVV',],
+        }],
       ],
       'sources': [
         '<!@pymod_do_main(GN-scraper "<(HIGHWAY_ROOT)/BUILD.gn"  "source_set.\\"libhwy.*?sources = ")',