AArch64: remove unnecessary pseudo-instruction.

Sufficiently twisted use of TableGen lets us write patterns directly for f16
(as an i16 promoted to i32) -> f32 conversion.

llvm-svn: 212933

2 files changed, 3 insertions, 15 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64ExpandPseudoInsts.cpp b/llvm/lib/Target/AArch64/AArch64ExpandPseudoInsts.cpp
index a76fd76e5ed..8839085c4a8 100644
--- a/llvm/lib/Target/AArch64/AArch64ExpandPseudoInsts.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ExpandPseudoInsts.cpp
@@ -634,19 +634,6 @@ bool AArch64ExpandPseudo::expandMI(MachineBasicBlock &MBB,
     return true;
   }
 
-  case AArch64::FCVTSHpseudo: {
-    MachineOperand Src = MI.getOperand(1);
-    Src.setImplicit();
-    unsigned SrcH =
-        TII->getRegisterInfo().getSubReg(Src.getReg(), AArch64::hsub);
-    auto MIB = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::FCVTSHr))
-                   .addOperand(MI.getOperand(0))
-                   .addReg(SrcH, RegState::Undef)
-                   .addOperand(Src);
-    transferImpOps(MI, MIB, MIB);
-    MI.eraseFromParent();
-    return true;
-  }
   case AArch64::LOADgot: {
     // Expand into ADRP + LDR.
     unsigned DstReg = MI.getOperand(0).getReg();
diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.td b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
index 1211fba60c2..3ec0212b416 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -2239,8 +2239,9 @@ def : Pat<(f32_to_f16 FPR32:$Rn),
                    (f32 (SUBREG_TO_REG (i32 0), (FCVTHSr FPR32:$Rn), hsub)),
                    GPR32))>;
 
-def FCVTSHpseudo : Pseudo<(outs FPR32:$Rd), (ins FPR32:$Rn),
-                          [(set (f32 FPR32:$Rd), (f16_to_f32 i32:$Rn))]>;
+def : Pat<(f32 (f16_to_f32 i32:$Rn)),
+          (FCVTSHr (EXTRACT_SUBREG (i32 (COPY_TO_REGCLASS i32:$Rn, FPR32)),
+                                   hsub))>;
 
 // When converting from f16 coming directly from a load, make sure we
 // load into the FPR16 registers rather than going through the GPRs.