Merge pull request #2088 from luhenry/upstream-riscv64

Make simdjson riscv64 aware

.github/workflows/riscv64.yml

@@ -0,0 +1,29 @@
+name: Ubuntu riscv64 (GCC 11)
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: uraimo/run-on-arch-action@v2
+        name: Test
+        id: runcmd
+        with:
+          arch: riscv64
+          distro: ubuntu_latest
+          githubToken: ${{ github.token }}
+          install: |
+            apt-get update -q -y
+            apt-get install -y cmake make g++
+          run: |
+            cmake -DCMAKE_BUILD_TYPE=Release -B build
+            cmake --build build -j=2
+            ctest --output-on-failure --test-dir build

include/simdjson/portability.h

@@ -36,6 +36,8 @@
 #define SIMDJSON_IS_X86_64 1
 #elif defined(__aarch64__) || defined(_M_ARM64)
 #define SIMDJSON_IS_ARM64 1
+#elif defined(__riscv) && __riscv_xlen == 64
+#define SIMDJSON_IS_RISCV64 1
 #elif defined(__PPC64__) || defined(_M_PPC64)
 #if defined(__ALTIVEC__)
 #define SIMDJSON_IS_PPC64_VMX 1