Unverified Commit 4f50fe92 authored by Joe Nash's avatar Joe Nash Committed by GitHub
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[AMDGPU][MC] Permit unneeded VOPD mov operands to be non-zero (#194060) 

Use ? instead of 0 in the tablegen definitions for VOPD containing
v_mov. This enables the instruction to be disassembled regardless of
what bits are in those fields, which helps diagnose broken code.
Previously, the disassembler would reject these.
parent cc2b2f54

llvm/lib/Target/AMDGPU/VOPDInstructions.td

+4 −4
Original line number Diff line number Diff line
@@ -148,16 +148,16 @@ class VOPD<dag outs, dag ins, string asm, VOP_Pseudo VDX, VOP_Pseudo VDY, 
           VOPD_Component XasVC, VOPD_Component YasVC, GFXGenD Gen>

    : VOPD_Base<outs, ins, asm, VDX, VDY, XasVC, YasVC, Gen>,

      VOPDe<XasVC.VOPDOp{3-0}, YasVC.VOPDOp{4-0}> {

  let Inst{16-9} = !if (!eq(VDX.Mnemonic, "v_mov_b32"), 0x0, vsrc1X);

  let Inst{48-41} = !if (!eq(VDY.Mnemonic, "v_mov_b32"), 0x0, vsrc1Y);

  let Inst{16-9} = !if (!eq(VDX.Mnemonic, "v_mov_b32"), ?, vsrc1X);

  let Inst{48-41} = !if (!eq(VDY.Mnemonic, "v_mov_b32"), ?, vsrc1Y);

}



class VOPD_MADK<dag outs, dag ins, string asm, VOP_Pseudo VDX, VOP_Pseudo VDY,

                VOPD_Component XasVC, VOPD_Component YasVC, GFXGenD Gen>

    : VOPD_Base<outs, ins, asm, VDX, VDY, XasVC, YasVC, Gen>,

      VOPD_MADKe<XasVC.VOPDOp{3-0}, YasVC.VOPDOp{4-0}> {

  let Inst{16-9} = !if (!eq(VDX.Mnemonic, "v_mov_b32"), 0x0, vsrc1X);

  let Inst{48-41} = !if (!eq(VDY.Mnemonic, "v_mov_b32"), 0x0, vsrc1Y);

  let Inst{16-9} = !if (!eq(VDX.Mnemonic, "v_mov_b32"), ?, vsrc1X);

  let Inst{48-41} = !if (!eq(VDY.Mnemonic, "v_mov_b32"), ?, vsrc1Y);

  let Size = 12;

  let FixedSize = 1;

}

llvm/test/MC/Disassembler/AMDGPU/gfx12_dasm_vopd_unused_operands.txt

0 → 100644
+25 −0
Original line number Diff line number Diff line 
# RUN: llvm-mc -triple=amdgcn -mcpu=gfx1200 -disassemble -show-encoding < %s | FileCheck %s -strict-whitespace --check-prefix=GFX12

# RUN: llvm-mc -triple=amdgcn -mcpu=gfx1250 -disassemble -show-encoding < %s | FileCheck %s -strict-whitespace --check-prefix=GFX12



# Test that VOPD instructions with v_dual_mov_b32 tolerate non-zero bits in

# the unused vsrc1 field.



# v_dual_mov_b32 v255, -1 :: v_dual_fmac_f32 v6, src_scc, v4

# With non-zero vsrc1X=0x42

0xc1,0x84,0x00,0xca,0xfd,0x08,0x06,0xff

# GFX12: v_dual_mov_b32 v255, -1 :: v_dual_fmac_f32 v6, src_scc, v4 ; encoding: [0xc1,0x00,0x00,0xca,0xfd,0x08,0x06,0xff]



# v_dual_add_f32 v255, -1, v4 :: v_dual_mov_b32 v6, src_scc

# With non-zero vsrc1Y=0x42

0xc1,0x08,0x10,0xc9,0xfd,0x84,0x06,0xff

# GFX12: v_dual_add_f32 v255, -1, v4 :: v_dual_mov_b32 v6, src_scc ; encoding: [0xc1,0x08,0x10,0xc9,0xfd,0x00,0x06,0xff]



# v_dual_mov_b32 v255, -1 :: v_dual_fmamk_f32 v6, src_scc, 0xaf123456, v255

# With non-zero vsrc1X=0x42

0xc1,0x84,0x04,0xca,0xfd,0xfe,0x07,0xff,0x56,0x34,0x12,0xaf

# GFX12: v_dual_mov_b32 v255, -1 :: v_dual_fmamk_f32 v6, src_scc, 0xaf123456, v255 ; encoding: [0xc1,0x00,0x04,0xca,0xfd,0xfe,0x07,0xff,0x56,0x34,0x12,0xaf]



# v_dual_fmamk_f32 v255, -1, 0xaf123456, v255 :: v_dual_mov_b32 v6, src_scc

# With non-zero vsrc1Y=0x42

0xc1,0xfe,0x91,0xc8,0xfd,0x84,0x06,0xff,0x56,0x34,0x12,0xaf

# GFX12: v_dual_fmamk_f32 v255, -1, 0xaf123456, v255 :: v_dual_mov_b32 v6, src_scc ; encoding: [0xc1,0xfe,0x91,0xc8,0xfd,0x00,0x06,0xff,0x56,0x34,0x12,0xaf]