[AArch64] Add support for -ffixed-x30
Add support for reserving LR in:
* the driver through `-ffixed-x30`
* cc1 through `-target-feature +reserve-x30`
* the backend through `-mattr=+reserve-x30`
* a subtarget feature `reserve-x30`
the same way we're doing for the other registers.
diff --git a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
index 4c034d4..e71655b 100644
--- a/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/AArch64.cpp
@@ -409,6 +409,9 @@
if (Args.hasArg(options::OPT_ffixed_x28))
Features.push_back("+reserve-x28");
+ if (Args.hasArg(options::OPT_ffixed_x30))
+ Features.push_back("+reserve-x30");
+
if (Args.hasArg(options::OPT_fcall_saved_x8))
Features.push_back("+call-saved-x8");
diff --git a/clang/test/Driver/aarch64-fixed-x-register.c b/clang/test/Driver/aarch64-fixed-x-register.c
index ed8e7c2..52f62e6 100644
--- a/clang/test/Driver/aarch64-fixed-x-register.c
+++ b/clang/test/Driver/aarch64-fixed-x-register.c
@@ -94,6 +94,10 @@
// RUN: FileCheck --check-prefix=CHECK-FIXED-X28 < %t %s
// CHECK-FIXED-X28: "-target-feature" "+reserve-x28"
+// RUN: %clang -target aarch64-none-gnu -ffixed-x30 -### %s 2> %t
+// RUN: FileCheck --check-prefix=CHECK-FIXED-X30 < %t %s
+// CHECK-FIXED-X30: "-target-feature" "+reserve-x30"
+
// Test multiple of reserve-x# options together.
// RUN: %clang -target aarch64-none-gnu \
// RUN: -ffixed-x1 \