Fix feature RAS assigned to ARMv8.1 when it should be ARMv8.2

[rogfer01]

Summary

Revision 271670 (which was comitted on behalf of me by @SjoerdMeijer) had a mistake where RAS extensions where assigned to 8.1 rather than 8.2.

[rogfer01]

Ping?

Thank you very much.

[t.p.northover]

What does this affect? It seems like it ought to be possible to write a test for it. (try to assemble something with v8.1a and check that RAS isn't accepted?)

Tim.

[rogfer01]

Indeed this does not have any effect. I could even remove the enumerator from the macro and nothing changes.

AArch64 has a similar AArch64::AEK_RAS in armv8.2-a and it is handled in AArch64::getExtensionFeatures (in lib/Support/TargetParser.cpp) but (unless I'm missing something very obvious) it is not called from anywhere.

Conversely, ARM::getExtensionFeatures is called from tools/clang/lib/Basic/Targets.cpp but does not handle ARM::AEK_RAS. Handling it like AArch64 does not have any effect either.

[rogfer01]

Closing since @richard.barton.arm opened D23500 for the same issue but on top of the new AArch64 TargetParser

[richard.barton.arm]

These macros are available for setting compiler-provided preprocessing macros like ACLE. We are not using any of the ARMv8.2-A ones because the ACLE has not caught up sufficiently with the architecture to have defined any.

include/llvm/Support/ARMTargetParser.def

ARM_ARCH("armv7e-m", AK_ARMV7EM, "7E-M", "v7em", ARMBuildAttrs::CPUArch::v7E_M,
           FK_NONE, (ARM::AEK_HWDIV | ARM::AEK_DSP))
 ARM_ARCH("armv8-a", AK_ARMV8A, "8-A", "v8", ARMBuildAttrs::CPUArch::v8_A,
          FK_CRYPTO_NEON_FP_ARMV8,
          (ARM::AEK_SEC | ARM::AEK_MP | ARM::AEK_VIRT | ARM::AEK_HWDIVARM |
           ARM::AEK_HWDIV | ARM::AEK_DSP | ARM::AEK_CRC))
 ARM_ARCH("armv8.1-a", AK_ARMV8_1A, "8.1-A", "v8.1a",
          ARMBuildAttrs::CPUArch::v8_A, FK_CRYPTO_NEON_FP_ARMV8,
          (ARM::AEK_SEC | ARM::AEK_MP | ARM::AEK_VIRT | ARM::AEK_HWDIVARM |
-          ARM::AEK_HWDIV | ARM::AEK_DSP | ARM::AEK_CRC | ARM::AEK_RAS))
+          ARM::AEK_HWDIV | ARM::AEK_DSP | ARM::AEK_CRC))
 ARM_ARCH("armv8.2-a", AK_ARMV8_2A, "8.2-A", "v8.2a",
          ARMBuildAttrs::CPUArch::v8_A, FK_CRYPTO_NEON_FP_ARMV8,
          (ARM::AEK_SEC | ARM::AEK_MP | ARM::AEK_VIRT | ARM::AEK_HWDIVARM |
-          ARM::AEK_HWDIV | ARM::AEK_DSP | ARM::AEK_CRC))
+          ARM::AEK_HWDIV | ARM::AEK_DSP | ARM::AEK_CRC | ARM::AEK_RAS))
 ARM_ARCH("armv8-m.base", AK_ARMV8MBaseline, "8-M.Baseline", "v8m.base",
           ARMBuildAttrs::CPUArch::v8_M_Base, FK_NONE, ARM::AEK_HWDIV)
 ARM_ARCH("armv8-m.main", AK_ARMV8MMainline, "8-M.Mainline", "v8m.main",
           ARMBuildAttrs::CPUArch::v8_M_Main, FK_FPV5_D16, ARM::AEK_HWDIV)
 // Non-standard Arch names.
 ARM_ARCH("iwmmxt", AK_IWMMXT, "iwmmxt", "", ARMBuildAttrs::CPUArch::v5TE,
           FK_NONE, ARM::AEK_NONE)
 ARM_ARCH("iwmmxt2", AK_IWMMXT2, "iwmmxt2", "", ARMBuildAttrs::CPUArch::v5TE,