[AArch64] Enable A53 erratum workaround (835769) by default for Android targets

[bsmith]

Summary

The patch causes the workaround for A53 erratum (835769) to be enabled by default for all AArch64 Android targets, the can still be overridden using the previously added -mno-fix-cortex-a53-835769 option.

[rengolin]

Hi Bradley,

If the Android guys are happy with this, I'm ok, too. Please wait for Stephen's approval, but otherwise, LGTM.

cheers,
--renato

[srhines]

LGTM. Thanks for getting this in.

[bsmith]

Committed as 219933, thanks!

lib/Driver/Tools.cpp

       CmdArgs.push_back("-aarch64-fix-cortex-a53-835769=1");
     else
       CmdArgs.push_back("-aarch64-fix-cortex-a53-835769=0");
+  } else if (Triple.getEnvironment() == llvm::Triple::Android) {
+    // Enabled A53 errata (835769) workaround by default on android
+    CmdArgs.push_back("-backend-option");
+    CmdArgs.push_back("-aarch64-fix-cortex-a53-835769=1");
   }
 
   // Setting -mno-global-merge disables the codegen global merge pass. Setting

test/CodeGen/aarch64-fix-cortex-a53-835769.c

+// REQUIRES: aarch64-registered-target
+
+// RUN: %clang -O3 -target aarch64-linux-eabi %s -S -o- \
+// RUN:   | FileCheck --check-prefix=CHECK-NO --check-prefix=CHECK %s
+// RUN: %clang -O3 -target aarch64-linux-eabi -mfix-cortex-a53-835769 %s -S -o- 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-YES --check-prefix=CHECK %s
+// RUN: %clang -O3 -target aarch64-linux-eabi -mno-fix-cortex-a53-835769 %s -S -o- 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-NO --check-prefix=CHECK %s
+
+// RUN: %clang -O3 -target aarch64-android-eabi %s -S -o- \
+// RUN:   | FileCheck --check-prefix=CHECK-YES --check-prefix=CHECK %s
+// RUN: %clang -O3 -target aarch64-android-eabi -mfix-cortex-a53-835769 %s -S -o- \
+// RUN:   | FileCheck --check-prefix=CHECK-YES --check-prefix=CHECK %s
+// RUN: %clang -O3 -target aarch64-android-eabi -mno-fix-cortex-a53-835769 %s -S -o- \
+// RUN:   | FileCheck --check-prefix=CHECK-NO --check-prefix=CHECK %s
+
+typedef long int64_t;
+
+int64_t f_load_madd_64(int64_t a, int64_t b, int64_t *c) {
+    int64_t result = a+b*(*c);
+    return result;
+}
+
+// CHECK: ldr
+// CHECK-YES-NEXT: nop
+// CHECK-NO-NEXT-NOT: nop
+// CHECK-NEXT: madd

test/Driver/aarch64-fix-cortex-a53-835769-cg.c

-// REQUIRES: aarch64-registered-target
-// RUN: %clang -O3 -target aarch64-linux-eabi %s -S -o- \
-// RUN:   | FileCheck --check-prefix=CHECK-NO --check-prefix=CHECK %s
-// RUN: %clang -O3 -target aarch64-linux-eabi -mfix-cortex-a53-835769 %s -S -o- 2>&1 \
-// RUN:   | FileCheck --check-prefix=CHECK-YES --check-prefix=CHECK %s
-// RUN: %clang -O3 -target aarch64-linux-eabi -mno-fix-cortex-a53-835769 %s -S -o- 2>&1 \
-// RUN:   | FileCheck --check-prefix=CHECK-NO --check-prefix=CHECK %s
-
-typedef long int64_t;
-
-int64_t f_load_madd_64(int64_t a, int64_t b, int64_t *c) {
-    int64_t result = a+b*(*c);
-    return result;
-}
-
-// CHECK: ldr
-// CHECK-YES-NEXT: nop
-// CHECK-NO-NEXT-NOT: nop
-// CHECK-NEXT: madd

test/Driver/aarch64-fix-cortex-a53-835769.c

 // RUN:   | FileCheck --check-prefix=CHECK-YES %s
 // RUN: %clang -target aarch64-linux-eabi -mno-fix-cortex-a53-835769 %s -### 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-NO %s
+
+// RUN: %clang -target aarch64-android-eabi %s -### 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-YES %s
+
 // CHECK-DEF-NOT: "-backend-option" "-aarch64-fix-cortex-a53-835769"
 // CHECK-YES: "-backend-option" "-aarch64-fix-cortex-a53-835769=1"
 // CHECK-NO: "-backend-option" "-aarch64-fix-cortex-a53-835769=0"