Add riscv cpu info detection.

* Supports:

 * The standard single-letter Vector detection.

 * Vector fp16 detection.

Signed-off-by: Darren Hsieh <darren.hsieh@sifive.com>
Change-Id: Ia7ee1bd8ec1a990f1b2b1700805942e99c0aa87b
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/4401738
Commit-Queue: Frank Barchard <fbarchard@chromium.org>
Reviewed-by: Frank Barchard <fbarchard@chromium.org>

5 files changed, 54 insertions, 0 deletions

diff --git a/unit_test/cpu_test.cc b/unit_test/cpu_test.cc
index 080778f5..3bd159f7 100644
--- a/unit_test/cpu_test.cc
+++ b/unit_test/cpu_test.cc
@@ -27,6 +27,14 @@ TEST_F(LibYUVBaseTest, TestCpuHas) {
   int has_neon = TestCpuFlag(kCpuHasNEON);
   printf("Has NEON %d\n", has_neon);
 #endif
+#if defined(__riscv) && defined(__linux__)
+  int has_riscv = TestCpuFlag(kCpuHasRISCV);
+  printf("Has RISCV %d\n", has_riscv);
+  int has_rvv = TestCpuFlag(kCpuHasRVV);
+  printf("Has RVV %d\n", has_rvv);
+  int has_rvvzvfh = TestCpuFlag(kCpuHasRVVZVFH);
+  printf("Has RVVZVFH %d\n", has_rvvzvfh);
+#endif
   int has_x86 = TestCpuFlag(kCpuHasX86);
   int has_sse2 = TestCpuFlag(kCpuHasSSE2);
   int has_ssse3 = TestCpuFlag(kCpuHasSSSE3);
@@ -164,6 +172,9 @@ TEST_F(LibYUVBaseTest, TestCompilerMacros) {
 #ifdef _WIN32
   printf("_WIN32 %d\n", _WIN32);
 #endif
+#ifdef __riscv
+  printf("__riscv %d\n", __riscv);
+#endif
 #ifdef GG_LONGLONG
   printf("GG_LONGLONG %d\n", GG_LONGLONG);
 #endif
@@ -264,6 +275,32 @@ TEST_F(LibYUVBaseTest, TestLinuxMipsMsa) {
   }
 }
 
+TEST_F(LibYUVBaseTest, TestLinuxRVV) {
+  if (FileExists("../../unit_test/testdata/riscv64.txt")) {
+    printf("Note: testing to load \"../../unit_test/testdata/riscv64.txt\"\n");
+
+    EXPECT_EQ(0, RiscvCpuCaps("../../unit_test/testdata/riscv64.txt"));
+    EXPECT_EQ(kCpuHasRVV,
+              RiscvCpuCaps("../../unit_test/testdata/riscv64_rvv.txt"));
+    EXPECT_EQ(kCpuHasRVV | kCpuHasRVVZVFH,
+              RiscvCpuCaps("../../unit_test/testdata/riscv64_rvv_zvfh.txt"));
+  } else {
+    printf(
+        "WARNING: unable to load "
+        "\"../../unit_test/testdata/riscv64.txt\"\n");
+  }
+#if defined(__linux__) && defined(__riscv)
+  if (FileExists("/proc/cpuinfo")) {
+    if (!(kCpuHasRVV & RiscvCpuCaps("/proc/cpuinfo"))) {
+      // This can happen on RVV emulator but /proc/cpuinfo is from host.
+      printf("WARNING: RVV build enabled but CPU does not have RVV\n");
+    }
+  } else {
+    printf("WARNING: unable to load \"/proc/cpuinfo\"\n");
+  }
+#endif
+}
+
 // TODO(fbarchard): Fix clangcl test of cpuflags.
 #ifdef _MSC_VER
 TEST_F(LibYUVBaseTest, DISABLED_TestSetCpuFlags) {
diff --git a/unit_test/testdata/riscv64.txt b/unit_test/testdata/riscv64.txt
new file mode 100644
index 00000000..fbb4200f
--- /dev/null
+++ b/unit_test/testdata/riscv64.txt
@@ -0,0 +1,4 @@
+processor       : 0
+hart            : 1
+isa             : rv64imac
+mmu             : sv48
\ No newline at end of file
diff --git a/unit_test/testdata/riscv64_rvv.txt b/unit_test/testdata/riscv64_rvv.txt
new file mode 100644
index 00000000..af1b3f36
--- /dev/null
+++ b/unit_test/testdata/riscv64_rvv.txt
@@ -0,0 +1,4 @@
+processor       : 0
+hart            : 1
+isa             : rv64imafdcv
+mmu             : sv48
\ No newline at end of file
diff --git a/unit_test/testdata/riscv64_rvv_zvfh.txt b/unit_test/testdata/riscv64_rvv_zvfh.txt
new file mode 100644
index 00000000..c416c1af
--- /dev/null
+++ b/unit_test/testdata/riscv64_rvv_zvfh.txt
@@ -0,0 +1,4 @@
+processor       : 0
+hart            : 1
+isa             : rv64imafdcv_zfh_zvfh
+mmu             : sv48
\ No newline at end of file
diff --git a/unit_test/unit_test.cc b/unit_test/unit_test.cc
index 61145a46..b66ebfab 100644
--- a/unit_test/unit_test.cc
+++ b/unit_test/unit_test.cc
@@ -88,6 +88,11 @@ int TestCpuEnv(int cpu_info) {
     cpu_info &= ~libyuv::kCpuHasLASX;
   }
 #endif
+#if defined(__riscv) && defined(__linux__)
+  if (TestEnv("LIBYUV_DISABLE_RVV")) {
+    cpu_info &= ~libyuv::kCpuHasRVV;
+  }
+#endif
 #if !defined(__pnacl__) && !defined(__CLR_VER) &&                   \
     (defined(__x86_64__) || defined(_M_X64) || defined(__i386__) || \
      defined(_M_IX86))