[gcc r11-6408] internal/cpu: add aarch64 support functions

[gcc r11-6408] internal/cpu: add aarch64 support functions

[Ian Lance Taylor]

https://gcc.gnu.org/g:5a4e0d121ab199d8a2036b219065f30f9f7411a3

commit r11-6408-g5a4e0d121ab199d8a2036b219065f30f9f7411a3
Author: Ian Lance Taylor <iant@golang.org>
Date:   Fri Jan 1 12:05:39 2021 -0800

    internal/cpu: add aarch64 support functions
    
    Patch from Andreas Schwab.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/281000

Diff:
---
 gcc/go/gofrontend/MERGE           |  2 +-
 libgo/go/internal/cpu/cpu_gccgo.c | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index e51285c7214..f4c99756d25 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-fa161cb71880cf80ef53fb4bf35dba8ee01af648
+2b5bdd22b7ec2fc13ae0f644c781f64c1a209500
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/libgo/go/internal/cpu/cpu_gccgo.c b/libgo/go/internal/cpu/cpu_gccgo.c
index da26f4d7407..6a20b394469 100644
--- a/libgo/go/internal/cpu/cpu_gccgo.c
+++ b/libgo/go/internal/cpu/cpu_gccgo.c
@@ -200,3 +200,29 @@ struct queryResult kdsaQuery() {
 }
 
 #endif /* defined(__s390x__)  */
+
+#ifdef __aarch64__
+
+uint64_t getisar0(void)
+  __asm__(GOSYM_PREFIX "internal_1cpu.getisar0")
+  __attribute__((no_split_stack));
+
+uint64_t getisar0() {
+       uint64_t isar0;
+
+       __asm__("mrs %0,id_aa64isar0_el1" : "=r"(isar0));
+       return isar0;
+}
+
+uint64_t getMIDR(void)
+  __asm__(GOSYM_PREFIX "internal_1cpu.getMIDR")
+  __attribute__((no_split_stack));
+
+uint64_t getMIDR() {
+       uint64_t MIDR;
+
+       __asm__("mrs %0,midr_el1" : "=r"(MIDR));
+       return MIDR;
+}
+
+#endif /* defined(__aarch64__) */