[PATCH] D105269: [X86] AVX512FP16 instructions enabling 6/6

[LuoYuanke via Phabricator via llvm-commits]

LuoYuanke added inline comments.


================
Comment at: clang/test/CodeGen/X86/avx512fp16-builtins.c:4223
+
+// CFC ADD PH
+
----------------
MADD?


================
Comment at: clang/test/CodeGen/X86/avx512fp16-builtins.c:4315
+
+// CF ADD PH
+
----------------
MADD?


================
Comment at: llvm/include/llvm/IR/IntrinsicsX86.td:5732
+
+  def int_x86_avx512fp16_mask_vfcmaddc_ph_128
+      : GCCBuiltin<"__builtin_ia32_vfcmaddcph128_mask">,
----------------
_cph?


================
Comment at: llvm/include/llvm/IR/IntrinsicsX86.td:5796
+                  [ IntrNoMem, ImmArg<ArgIndex<4>> ]>;
+  def int_x86_avx512fp16_mask_vfmaddc_sh
+      : GCCBuiltin<"__builtin_ia32_vfmaddcsh_mask">,
----------------
_csh?


================
Comment at: llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp:3902
+  case X86::VFCMADDCSHZr:
+  case X86::VFCMADDCSHZrb:
+  case X86::VFCMADDCSHZrbk:
----------------
"b" means rounding. Right?


================
Comment at: llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp:3948
+    for (unsigned i = 2; i < Inst.getNumOperands(); i++)
+      if (Inst.getOperand(i).isReg() && Dest == Inst.getOperand(i).getReg())
+        return Warning(Ops[0]->getStartLoc(), "Destination register should be "
----------------
Sorry, I didn't find the constrain in the spec.


================
Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:47289
+        return 0;
+      if (RHS->getOpcode() == ISD::BITCAST && RHS.hasOneUse() &&
+          (RHS->getOperand(0)->getOpcode() == X86ISD::VFMULC ||
----------------
Can swap LHS and RHS reduce some redundant code?


================
Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:47296
+    };
+    int MulId = getMulId();
+    const TargetOptions &Options = DAG.getTarget().Options;
----------------
The lambda seems only be called once.


================
Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:47298
+    const TargetOptions &Options = DAG.getTarget().Options;
+    if ((Options.AllowFPOpFusion == FPOpFusion::Fast || Options.UnsafeFPMath) &&
+        MulId < 2 && Subtarget.hasFP16() && IsAdd &&
----------------
Is it possible fast and non-fast instruction is mixed due to inline? Shall we check the instruction AllowContract flag?


================
Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:47359
+//  t23: v16f32 = X86ISD::VFCMULC[X86ISD::VFMULC]
+//  t8, t22
+//  t24: v32f16 = bitcast t23
----------------
Merge it to previous line.


================
Comment at: llvm/lib/Target/X86/X86InstrAVX512.td:5781
+                     (MaskOpNode  _.RC:$src1, (_.VT (_.BroadcastLdFrag addr:$src2))),
+                     0, 0, 0, ClobberConstraint>,
                      EVEX_4V, EVEX_B,
----------------
Moving ClobberConstraint before IsCommutable  saves the code for default value?


================
Comment at: llvm/lib/Target/X86/X86InstrAVX512.td:13604
+
+  defm VFMULCPH  : avx512_cfmbinop_common<0xD6, "vfmulcph", x86vfmulc, x86vfmulc,
+                                    x86vfmulcRnd>, T_MAP6XS, EVEX_CD8<32, CD8VF>;
----------------
The name seems not accurate. Is it cfmop for mul and cfmaop for fma?


================
Comment at: llvm/lib/Target/X86/X86InstrAVX512.td:13640
+                        (v4f32 (OpNode VR128X:$src1, VR128X:$src2)),
+                        0, 0, 0, X86selects, "@earlyclobber $dst">, Sched<[sched.XMM]>;
+    defm rm : AVX512_maskable<opc, MRMSrcMem, f32x_info, (outs VR128X:$dst),
----------------
I didn't see this flag for other scalar instructions, why we need it for complex instruction?


================
Comment at: llvm/lib/Target/X86/X86InstrFoldTables.cpp:1852
+  { X86::VFCMULCPHZrr,             X86::VFCMULCPHZrm,             0 },
+  { X86::VFCMULCSHZrr,             X86::VFCMULCSHZrm,             TB_NO_REVERSE },
   { X86::VFMADDPD4Yrr,             X86::VFMADDPD4Ymr,             0 },
----------------
Why FR32X version is not needed for complex scalar instructions?


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  https://reviews.llvm.org/D105269/new/

https://reviews.llvm.org/D105269