[AMDGPU] Add MC layer support for v_fmac_legacy_f32

[foad]

Summary

This instruction was introduced in GFX10.3, reusing the opcode of
v_mac_legacy_f32 from GFX10.1.

[arsenm]

llvm/test/MC/AMDGPU/gfx1030_unsupported.s

1

The sutarget features are broken and should be all lowercase

[rampitec]

It also seems to lack changes in SIFoldOperands, SIInstrInfo::FoldImmediate, SIInstrInfo::convertToThreeAddress, SIInstrInfo::canShrink. I think these can go in a separate change.

[foad]

In D89247#2325783, @rampitec wrote:

It also seems to lack changes in SIFoldOperands, SIInstrInfo::FoldImmediate, SIInstrInfo::convertToThreeAddress, SIInstrInfo::canShrink. I think these can go in a separate change.

Right. I'll change the summary to make it clear that this just adds asm/dis support.

llvm/test/MC/AMDGPU/gfx1030_unsupported.s

1

Do you mean they're broken in some other way, as well as not being lowercase?

[rampitec]

llvm/test/MC/AMDGPU/gfx1030_unsupported.s

1

Shall be enough just to change the case. Subpar, but on par with the rest of the tests.

[foad]

Lowercase subtarget feature names.

[rampitec]

LGTM

llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp

if (AMDGPU::getNamedOperandIdx(Opc, AMDGPU::OpName::omod) != -1) {
     addOptionalImmOperand(Inst, Operands, OptionalIdx, AMDGPUOperand::ImmTyOModSI);
   }
 
   // Special case v_mac_{f16, f32} and v_fmac_{f16, f32} (gfx906/gfx10+):
   // it has src2 register operand that is tied to dst operand
   // we don't allow modifiers for this operand in assembler so src2_modifiers
   // should be 0.
   if (Opc == AMDGPU::V_MAC_F32_e64_gfx6_gfx7 ||
       Opc == AMDGPU::V_MAC_F32_e64_gfx10 ||
       Opc == AMDGPU::V_MAC_F32_e64_vi ||
       Opc == AMDGPU::V_MAC_LEGACY_F32_e64_gfx6_gfx7 ||
       Opc == AMDGPU::V_MAC_LEGACY_F32_e64_gfx10 ||
       Opc == AMDGPU::V_MAC_F16_e64_vi ||
       Opc == AMDGPU::V_FMAC_F32_e64_gfx10 ||
       Opc == AMDGPU::V_FMAC_F32_e64_vi ||
+      Opc == AMDGPU::V_FMAC_LEGACY_F32_e64_gfx10 ||
       Opc == AMDGPU::V_FMAC_F16_e64_gfx10) {
     auto it = Inst.begin();
     std::advance(it, AMDGPU::getNamedOperandIdx(Opc, AMDGPU::OpName::src2_modifiers));
     it = Inst.insert(it, MCOperand::createImm(0)); // no modifiers for src2
     ++it;
     Inst.insert(it, Inst.getOperand(0)); // src2 = dst
   }
 }

llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp

DecodeStatus AMDGPUDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
   if (Res && (MI.getOpcode() == AMDGPU::V_MAC_F32_e64_vi ||
               MI.getOpcode() == AMDGPU::V_MAC_F32_e64_gfx6_gfx7 ||
               MI.getOpcode() == AMDGPU::V_MAC_F32_e64_gfx10 ||
               MI.getOpcode() == AMDGPU::V_MAC_LEGACY_F32_e64_gfx6_gfx7 ||
               MI.getOpcode() == AMDGPU::V_MAC_LEGACY_F32_e64_gfx10 ||
               MI.getOpcode() == AMDGPU::V_MAC_F16_e64_vi ||
               MI.getOpcode() == AMDGPU::V_FMAC_F32_e64_vi ||
               MI.getOpcode() == AMDGPU::V_FMAC_F32_e64_gfx10 ||
+              MI.getOpcode() == AMDGPU::V_FMAC_LEGACY_F32_e64_gfx10 ||
               MI.getOpcode() == AMDGPU::V_FMAC_F16_e64_gfx10)) {
     // Insert dummy unused src2_modifiers.
     insertNamedMCOperand(MI, MCOperand::createImm(0),
                          AMDGPU::OpName::src2_modifiers);
   }
 
   if (Res && (MCII->get(MI.getOpcode()).TSFlags & SIInstrFlags::MIMG)) {
     int VAddr0Idx =

llvm/lib/Target/AMDGPU/VOP2Instructions.td

 
 } // End SubtargetPredicate = Has16BitInsts
 
 let SubtargetPredicate = HasDLInsts in {
 
 defm V_XNOR_B32 : VOP2Inst <"v_xnor_b32", VOP_I32_I32_I32>;
 
 let Constraints = "$vdst = $src2",
-    DisableEncoding="$src2",
+    DisableEncoding = "$src2",
     isConvertibleToThreeAddress = 1,
-    isCommutable = 1 in {
+    isCommutable = 1 in
 defm V_FMAC_F32 : VOP2Inst <"v_fmac_f32", VOP_MAC_F32>;
-}
 
 } // End SubtargetPredicate = HasDLInsts
 
+let SubtargetPredicate = HasNoMadMacF32Insts in {
+
+let Constraints = "$vdst = $src2",
+    DisableEncoding = "$src2",
+    isConvertibleToThreeAddress = 1,
+    isCommutable = 1 in
+defm V_FMAC_LEGACY_F32 : VOP2Inst <"v_fmac_legacy_f32", VOP_MAC_LEGACY_F32>;
+
+} // End SubtargetPredicate = HasNoMadMacF32Insts
+
 let Constraints = "$vdst = $src2",
       DisableEncoding="$src2",
       isConvertibleToThreeAddress = 1,
       isCommutable = 1,
       IsDOT = 1 in {
   let SubtargetPredicate = HasDot5Insts in
     defm V_DOT2C_F32_F16 : VOP2Inst<"v_dot2c_f32_f16", VOP_DOT_ACC_F32_V2F16>;
   let SubtargetPredicate = HasDot6Insts in

 multiclass VOP2_Real_gfx10_with_name<bits<6> op, string opName,
                                      string asmName> :
   VOP2_Real_e32_gfx10_with_name<op, opName, asmName>,
   VOP2_Real_e64_gfx10_with_name<op, opName, asmName>,
   VOP2_Real_sdwa_gfx10_with_name<op, opName, asmName>,
   VOP2_Real_dpp_gfx10_with_name<op, opName, asmName>,
   VOP2_Real_dpp8_gfx10_with_name<op, opName, asmName>;
 
-defm V_XNOR_B32      : VOP2_Real_gfx10<0x01e>;
-defm V_FMAC_F32      : VOP2_Real_gfx10<0x02b>;
-defm V_FMAMK_F32     : VOP2Only_Real_MADK_gfx10<0x02c>;
-defm V_FMAAK_F32     : VOP2Only_Real_MADK_gfx10<0x02d>;
-defm V_ADD_F16       : VOP2_Real_gfx10<0x032>;
-defm V_SUB_F16       : VOP2_Real_gfx10<0x033>;
-defm V_SUBREV_F16    : VOP2_Real_gfx10<0x034>;
-defm V_MUL_F16       : VOP2_Real_gfx10<0x035>;
-defm V_FMAC_F16      : VOP2_Real_gfx10<0x036>;
-defm V_FMAMK_F16     : VOP2Only_Real_MADK_gfx10<0x037>;
-defm V_FMAAK_F16     : VOP2Only_Real_MADK_gfx10<0x038>;
-defm V_MAX_F16       : VOP2_Real_gfx10<0x039>;
-defm V_MIN_F16       : VOP2_Real_gfx10<0x03a>;
-defm V_LDEXP_F16     : VOP2_Real_gfx10<0x03b>;
-defm V_PK_FMAC_F16   : VOP2_Real_e32_gfx10<0x03c>;
+// NB: Same opcode as v_mac_legacy_f32
+let DecoderNamespace = "GFX10_B" in
+defm V_FMAC_LEGACY_F32 : VOP2_Real_gfx10<0x006>;
+
+defm V_XNOR_B32        : VOP2_Real_gfx10<0x01e>;
+defm V_FMAC_F32        : VOP2_Real_gfx10<0x02b>;
+defm V_FMAMK_F32       : VOP2Only_Real_MADK_gfx10<0x02c>;
+defm V_FMAAK_F32       : VOP2Only_Real_MADK_gfx10<0x02d>;
+defm V_ADD_F16         : VOP2_Real_gfx10<0x032>;
+defm V_SUB_F16         : VOP2_Real_gfx10<0x033>;
+defm V_SUBREV_F16      : VOP2_Real_gfx10<0x034>;
+defm V_MUL_F16         : VOP2_Real_gfx10<0x035>;
+defm V_FMAC_F16        : VOP2_Real_gfx10<0x036>;
+defm V_FMAMK_F16       : VOP2Only_Real_MADK_gfx10<0x037>;
+defm V_FMAAK_F16       : VOP2Only_Real_MADK_gfx10<0x038>;
+defm V_MAX_F16         : VOP2_Real_gfx10<0x039>;
+defm V_MIN_F16         : VOP2_Real_gfx10<0x03a>;
+defm V_LDEXP_F16       : VOP2_Real_gfx10<0x03b>;
+defm V_PK_FMAC_F16     : VOP2_Real_e32_gfx10<0x03c>;
 
 // VOP2 no carry-in, carry-out.
 defm V_ADD_NC_U32 :
   VOP2_Real_gfx10_with_name<0x025, "V_ADD_U32", "v_add_nc_u32">;
 defm V_SUB_NC_U32 :
   VOP2_Real_gfx10_with_name<0x026, "V_SUB_U32", "v_sub_nc_u32">;
 defm V_SUBREV_NC_U32 :
   VOP2_Real_gfx10_with_name<0x027, "V_SUBREV_U32", "v_subrev_nc_u32">;

llvm/test/MC/AMDGPU/gfx1011_err.s

 // GFX10: error: instruction not supported on this GPU
 
 s_getreg_b32 s2, hwreg(HW_REG_SHADER_CYCLES)
 // GFX10: error: specified hardware register is not supported on this GPU
 
 v_fma_legacy_f32 v0, v1, v2, v3
 // GFX10: error: instruction not supported on this GPU
 
+v_fmac_legacy_f32 v0, v1, v2
+// GFX10: error: instruction not supported on this GPU
+
 image_bvh_intersect_ray v[4:7], v[9:24], s[4:7]
 // GFX10: error: instruction not supported on this GPU
 
 image_bvh_intersect_ray v[4:7], v[9:16], s[4:7] a16
 // GFX10: error: instruction not supported on this GPU
 
 image_bvh64_intersect_ray v[4:7], v[9:24], s[4:7]
 // GFX10: error: instruction not supported on this GPU

llvm/test/MC/AMDGPU/gfx1030_new.s

 // GFX10: encoding: [0x00,0x00,0x40,0xd5,0x01,0x05,0x0e,0x04]
 
 v_fma_legacy_f32 v0, v1, |v2|, -v3
 // GFX10: encoding: [0x00,0x02,0x40,0xd5,0x01,0x05,0x0e,0x84]
 
 v_fma_legacy_f32 v0, s1, 2.0, -v3
 // GFX10: encoding: [0x00,0x00,0x40,0xd5,0x01,0xe8,0x0d,0x84]
 
+v_fmac_legacy_f32 v0, v1, v2
+// GFX10: encoding: [0x01,0x05,0x00,0x0c]
+
+v_fmac_legacy_f32 v0, |v1|, -v2
+// GFX10: encoding: [0x00,0x01,0x06,0xd5,0x01,0x05,0x02,0x40]
+
+v_fmac_legacy_f32 v0, s1, 2.0
+// GFX10: encoding: [0x00,0x00,0x06,0xd5,0x01,0xe8,0x01,0x00]
+
 image_bvh_intersect_ray v[4:7], v[9:24], s[4:7]
 // GFX10: encoding: [0x01,0x9f,0x98,0xf1,0x09,0x04,0x01,0x00]
 
 image_bvh_intersect_ray v[4:7], v[9:16], s[4:7] a16
 // GFX10: encoding: [0x01,0x9f,0x98,0xf1,0x09,0x04,0x01,0x40]
 
 image_bvh64_intersect_ray v[4:7], v[9:24], s[4:7]
 // GFX10: encoding: [0x01,0x9f,0x9c,0xf1,0x09,0x04,0x01,0x00]

llvm/test/MC/AMDGPU/gfx1030_unsupported.s

+// RUN: not llvm-mc -arch=amdgcn -mcpu=gfx1030 -mattr=+WavefrontSize32,-WavefrontSize64 %s 2>&1 | FileCheck --implicit-check-not=error: %s
+// RUN: not llvm-mc -arch=amdgcn -mcpu=gfx1030 -mattr=-WavefrontSize32,+WavefrontSize64 %s 2>&1 | FileCheck --implicit-check-not=error: %s
+
+//===----------------------------------------------------------------------===//
+// Unsupported dpp variants.
+//===----------------------------------------------------------------------===//
+
+v_fmac_legacy_f32_dpp v255, v1, v2 quad_perm:[0,1,2,3] row_mask:0x0 bank_mask:0x0
+// CHECK: :[[@LINE-1]]:{{[0-9]+}}: error: dpp variant of this instruction is not supported
+
+//===----------------------------------------------------------------------===//
+// Unsupported sdwa variants.
+//===----------------------------------------------------------------------===//
+
+v_fmac_legacy_f32_sdwa v255, v1, v2 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:DWORD
+// CHECK: :[[@LINE-1]]:{{[0-9]+}}: error: sdwa variant of this instruction is not supported

llvm/test/MC/Disassembler/AMDGPU/gfx1030_dasm_new.txt

 0x00,0x00,0x40,0xd5,0x01,0x05,0x0e,0x04
 
 # GFX10: v_fma_legacy_f32 v0, v1, |v2|, -v3
 0x00,0x02,0x40,0xd5,0x01,0x05,0x0e,0x84
 
 # GFX10: v_fma_legacy_f32 v0, s1, 2.0, -v3
 0x00,0x00,0x40,0xd5,0x01,0xe8,0x0d,0x84
 
+# GFX10: v_fmac_legacy_f32_e32 v0, v1, v2
+0x01,0x05,0x00,0x0c
+
+# GFX10: v_fmac_legacy_f32_e64 v0, |v1|, -v2
+0x00,0x01,0x06,0xd5,0x01,0x05,0x02,0x40
+
+# GFX10: v_fmac_legacy_f32_e64 v0, s1, 2.0
+0x00,0x00,0x06,0xd5,0x01,0xe8,0x01,0x00
+
 # GFX10: image_bvh_intersect_ray v[4:7], v[9:24], s[4:7]
 0x01,0x9f,0x98,0xf1,0x09,0x04,0x01,0x00
 
 # GFX10: image_bvh_intersect_ray v[4:7], v[9:16], s[4:7] a16
 0x01,0x9f,0x98,0xf1,0x09,0x04,0x01,0x40
 
 # GFX10: image_bvh64_intersect_ray v[4:7], v[9:24], s[4:7]
 0x01,0x9f,0x9c,0xf1,0x09,0x04,0x01,0x00