compiler/rustc_codegen_cranelift/src/intrinsics/llvm.rs

   1 //! Emulate LLVM intrinsics
   2
   3 use crate::intrinsics::*;
   4 use crate::prelude::*;
   5
   6 use rustc_middle::ty::subst::SubstsRef;
   7
   8 pub(crate) fn codegen_llvm_intrinsic_call<'tcx>(
   9     fx: &mut FunctionCx<'_, '_, 'tcx>,
  10     intrinsic: &str,
  11     substs: SubstsRef<'tcx>,
  12     args: &[mir::Operand<'tcx>],
  13     ret: CPlace<'tcx>,
  14     target: Option<BasicBlock>,
  15 ) {
  16     if intrinsic.starts_with("llvm.aarch64") {
  17         return llvm_aarch64::codegen_aarch64_llvm_intrinsic_call(
  18             fx, intrinsic, substs, args, ret, target,
  19         );
  20     }
  21     if intrinsic.starts_with("llvm.x86") {
  22         return llvm_x86::codegen_x86_llvm_intrinsic_call(fx, intrinsic, substs, args, ret, target);
  23     }
  24
  25     match intrinsic {
  26         _ if intrinsic.starts_with("llvm.ctlz.v") => {
  27             intrinsic_args!(fx, args => (a); intrinsic);
  28
  29             simd_for_each_lane(fx, a, ret, &|fx, _lane_ty, _res_lane_ty, lane| {
  30                 fx.bcx.ins().clz(lane)
  31             });
  32         }
  33
  34         _ if intrinsic.starts_with("llvm.ctpop.v") => {
  35             intrinsic_args!(fx, args => (a); intrinsic);
  36
  37             simd_for_each_lane(fx, a, ret, &|fx, _lane_ty, _res_lane_ty, lane| {
  38                 fx.bcx.ins().popcnt(lane)
  39             });
  40         }
  41
  42         _ => {
  43             fx.tcx
  44                 .sess
  45                 .warn(&format!("unsupported llvm intrinsic {}; replacing with trap", intrinsic));
  46             crate::trap::trap_unimplemented(fx, intrinsic);
  47             return;
  48         }
  49     }
  50
  51     let dest = target.expect("all llvm intrinsics used by stdlib should return");
  52     let ret_block = fx.get_block(dest);
  53     fx.bcx.ins().jump(ret_block, &[]);
  54 }