[AArch64] Add command-line option for Execution and Data Prediction Instructions

[dnsampaio]

Summary

Prediction control instructions are only mandatory from v8.5a
onwards but is optional from Armv8.0-A. This patch adds a command
line option to enable it by it's own.

[javed.absar]

LGTM but will wait for a while to allow others comment as well, if necessary.

include/llvm/Support/AArch64TargetParser.h

enum ArchExtKind : unsigned {
   AEK_SHA3 =        1 << 14,
   AEK_SHA2 =        1 << 15,
   AEK_AES =         1 << 16,
   AEK_FP16FML =     1 << 17,
   AEK_RAND =        1 << 18,
   AEK_MTE =         1 << 19,
   AEK_SSBS =        1 << 20,
   AEK_SB =          1 << 21,
+  AEK_PREDRES =     1 << 22,
 };
 
 enum class ArchKind {
 #define AARCH64_ARCH(NAME, ID, CPU_ATTR, SUB_ARCH, ARCH_ATTR, ARCH_FPU, ARCH_BASE_EXT) ID,
 #include "AArch64TargetParser.def"
 };
 
 const ARM::ArchNames<ArchKind> AArch64ARCHNames[] = {

include/llvm/Support/AArch64TargetParser.def

 AARCH64_ARCH_EXT_NAME("profile",  AArch64::AEK_PROFILE,  "+spe",  "-spe")
 AARCH64_ARCH_EXT_NAME("ras",      AArch64::AEK_RAS,      "+ras",  "-ras")
 AARCH64_ARCH_EXT_NAME("sve",      AArch64::AEK_SVE,      "+sve",  "-sve")
 AARCH64_ARCH_EXT_NAME("rcpc",     AArch64::AEK_RCPC,     "+rcpc", "-rcpc")
 AARCH64_ARCH_EXT_NAME("rng",      AArch64::AEK_RAND,     "+rand",  "-rand")
 AARCH64_ARCH_EXT_NAME("memtag",   AArch64::AEK_MTE,      "+mte",   "-mte")
 AARCH64_ARCH_EXT_NAME("ssbs",     AArch64::AEK_SSBS,     "+ssbs",  "-ssbs")
 AARCH64_ARCH_EXT_NAME("sb",       AArch64::AEK_SB,       "+sb",    "-sb")
+AARCH64_ARCH_EXT_NAME("predres",  AArch64::AEK_PREDRES,  "+predres", "-predres")
 #undef AARCH64_ARCH_EXT_NAME
 
 #ifndef AARCH64_CPU_NAME
 #define AARCH64_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT)
 #endif
 AARCH64_CPU_NAME("cortex-a35", ARMV8A, FK_CRYPTO_NEON_FP_ARMV8, false,
                 (AArch64::AEK_CRC))
 AARCH64_CPU_NAME("cortex-a53", ARMV8A, FK_CRYPTO_NEON_FP_ARMV8, true,

unittests/Support/TargetParserTest.cpp

const char *ArchExt[][4] = {{"crc", "nocrc", "+crc", "-crc"},
                               {"lse", "nolse", "+lse", "-lse"},
                               {"rdm", "nordm", "+rdm", "-rdm"},
                               {"sve", "nosve", "+sve", "-sve"},
                               {"dotprod", "nodotprod", "+dotprod", "-dotprod"},
                               {"rcpc", "norcpc", "+rcpc", "-rcpc" },
                               {"rng", "norng", "+rand", "-rand"},
                               {"memtag", "nomemtag", "+mte", "-mte"},
                               {"ssbs", "nossbs", "+ssbs", "-ssbs"},
-                              {"sb", "nosb", "+sb", "-sb"}};
+                              {"sb", "nosb", "+sb", "-sb"},
+                              {"predres", "nopredres", "+predres", "-predres"}
+};
 
   for (unsigned i = 0; i < array_lengthof(ArchExt); i++) {
     EXPECT_EQ(StringRef(ArchExt[i][2]),
               AArch64::getArchExtFeature(ArchExt[i][0]));
     EXPECT_EQ(StringRef(ArchExt[i][3]),
               AArch64::getArchExtFeature(ArchExt[i][1]));
   }
 }
 }