[AArch64] Implement __jcvt intrinsic from Armv8.3-A

The jcvt intrinsic defined in ACLE [1] is available when ARM_FEATURE_JCVT is defined.

This change introduces the AArch64 intrinsic, wires it up to the instruction and a new clang builtin function.
The __ARM_FEATURE_JCVT macro is now defined when an Armv8.3-A or higher target is used.
I've implemented the target detection logic in Clang so that this feature is enabled for architectures from armv8.3-a onwards (so -march=armv8.4-a also enables this, for example).

make check-all didn't show any new failures.

[1] https://developer.arm.com/docs/101028/latest/data-processing-intrinsics

Differential Revision: https://reviews.llvm.org/D64495

llvm-svn: 366197

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index c58d1018fa0..acaa81ae8a9 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -6977,6 +6977,14 @@ Value *CodeGenFunction::EmitAArch64BuiltinExpr(unsigned BuiltinID,
         CGM.getIntrinsic(Intrinsic::bitreverse, Arg->getType()), Arg, "rbit");
   }
 
+  if (BuiltinID == AArch64::BI__builtin_arm_jcvt) {
+    assert((getContext().getTypeSize(E->getType()) == 32) &&
+           "__jcvt of unusual size!");
+    llvm::Value *Arg = EmitScalarExpr(E->getArg(0));
+    return Builder.CreateCall(
+        CGM.getIntrinsic(Intrinsic::aarch64_fjcvtzs), Arg);
+  }
+
   if (BuiltinID == AArch64::BI__clear_cache) {
     assert(E->getNumArgs() == 2 && "__clear_cache takes 2 arguments");
     const FunctionDecl *FD = E->getDirectCallee();