[AArch64][SVE] Asm: Support for SVE condition code aliases

SVE overloads the AArch64 PSTATE condition flags and introduces
a set of condition code aliases for the assembler. The 
details are described in section 2.2 of the architecture
reference manual supplement for SVE.

In short:

  SVE alias =>  AArch64 name
  --------------------------
  NONE      => EQ
  ANY       => NE
  NLAST     => HS
  LAST      => LO
  FIRST     => MI
  NFRST     => PL
  PMORE     => HI
  PLAST     => LS
  TCONT     => GE
  TSTOP     => LT

Reviewers: rengolin, fhahn, SjoerdMeijer, samparker, javed.absar

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D48869

llvm-svn: 336245

llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

@@ -2523,6 +2523,22 @@ AArch64CC::CondCode AArch64AsmParser::parseCondCodeString(StringRef Cond) {
                     .Case("al", AArch64CC::AL)
                     .Case("nv", AArch64CC::NV)
                     .Default(AArch64CC::Invalid);
+
+  if (CC == AArch64CC::Invalid &&
+      getSTI().getFeatureBits()[AArch64::FeatureSVE])
+    CC = StringSwitch<AArch64CC::CondCode>(Cond.lower())
+                    .Case("none",  AArch64CC::EQ)
+                    .Case("any",   AArch64CC::NE)
+                    .Case("nlast", AArch64CC::HS)
+                    .Case("last",  AArch64CC::LO)
+                    .Case("first", AArch64CC::MI)
+                    .Case("nfrst", AArch64CC::PL)
+                    .Case("pmore", AArch64CC::HI)
+                    .Case("plast", AArch64CC::LS)
+                    .Case("tcont", AArch64CC::GE)
+                    .Case("tstop", AArch64CC::LT)
+                    .Default(AArch64CC::Invalid);
+
   return CC;
 }
 

llvm/test/MC/AArch64/SVE/condtion-codes.s

@@ -0,0 +1,66 @@
+// RUN: llvm-mc -triple aarch64 -show-encoding -mattr=+sve < %s | FileCheck %s
+// RUN: not llvm-mc -triple aarch64 -show-encoding -mattr=-sve < %s 2>&1 | FileCheck %s --check-prefix=CHECK-DIAG
+
+//------------------------------------------------------------------------------
+// Condition code aliases for SVE
+//------------------------------------------------------------------------------
+
+        b.none lbl
+// CHECK: b.eq lbl     // encoding: [0bAAA00000,A,A,0x54]
+// CHECK-NEXT:         //   fixup A - offset: 0, value: lbl, kind: fixup_aarch64_pcrel_branch19
+// CHECK-DIAG:  invalid condition code
+// CHECK-DIAG-NEXT:  b.none lbl
+
+        b.any lbl
+// CHECK: b.ne lbl     // encoding: [0bAAA00001,A,A,0x54]
+// CHECK-NEXT:         //   fixup A - offset: 0, value: lbl, kind: fixup_aarch64_pcrel_branch19
+// CHECK-DIAG:  invalid condition code
+// CHECK-DIAG-NEXT:  b.any lbl
+
+        b.nlast lbl
+// CHECK: b.hs lbl     // encoding: [0bAAA00010,A,A,0x54]
+// CHECK-NEXT:         //   fixup A - offset: 0, value: lbl, kind: fixup_aarch64_pcrel_branch19
+// CHECK-DIAG:  invalid condition code
+// CHECK-DIAG-NEXT:  b.nlast lbl
+
+        b.last lbl
+// CHECK: b.lo lbl     // encoding: [0bAAA00011,A,A,0x54]
+// CHECK-NEXT:         //   fixup A - offset: 0, value: lbl, kind: fixup_aarch64_pcrel_branch19
+// CHECK-DIAG:  invalid condition code
+// CHECK-DIAG-NEXT:  b.last lbl
+
+        b.first lbl
+// CHECK: b.mi lbl     // encoding: [0bAAA00100,A,A,0x54]
+// CHECK-NEXT:         //   fixup A - offset: 0, value: lbl, kind: fixup_aarch64_pcrel_branch19
+// CHECK-DIAG:  invalid condition code
+// CHECK-DIAG-NEXT:  b.first lbl
+
+        b.nfrst lbl
+// CHECK: b.pl lbl     // encoding: [0bAAA00101,A,A,0x54]
+// CHECK-NEXT:         //   fixup A - offset: 0, value: lbl, kind: fixup_aarch64_pcrel_branch19
+// CHECK-DIAG:  invalid condition code
+// CHECK-DIAG-NEXT:  b.nfrst lbl
+
+        b.pmore lbl
+// CHECK: b.hi lbl     // encoding: [0bAAA01000,A,A,0x54]
+// CHECK-NEXT:         //   fixup A - offset: 0, value: lbl, kind: fixup_aarch64_pcrel_branch19
+// CHECK-DIAG:  invalid condition code
+// CHECK-DIAG-NEXT:  b.pmore lbl
+
+        b.plast lbl
+// CHECK: b.ls lbl     // encoding: [0bAAA01001,A,A,0x54]
+// CHECK-NEXT:         //   fixup A - offset: 0, value: lbl, kind: fixup_aarch64_pcrel_branch19
+// CHECK-DIAG:  invalid condition code
+// CHECK-DIAG-NEXT:  b.plast lbl
+
+        b.tcont lbl
+// CHECK: b.ge lbl     // encoding: [0bAAA01010,A,A,0x54]
+// CHECK-NEXT:         //   fixup A - offset: 0, value: lbl, kind: fixup_aarch64_pcrel_branch19
+// CHECK-DIAG:  invalid condition code
+// CHECK-DIAG-NEXT:  b.tcont lbl
+
+        b.tstop lbl
+// CHECK: b.lt lbl     // encoding: [0bAAA01011,A,A,0x54]
+// CHECK-NEXT:         //   fixup A - offset: 0, value: lbl, kind: fixup_aarch64_pcrel_branch19
+// CHECK-DIAG:  invalid condition code
+// CHECK-DIAG-NEXT:  b.tstop lbl