subw

Subtract word

This instruction is defined by:

Encoding

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Synopsis

Subtract the 32-bit values in rs2 from rs1, and store the sign-extended result in rd

Access

M

HS

U

VS

VU

Always

Always

Always

Always

Always

Decode Variables

Bits<5> rs2 = $encoding[24:20];
Bits<5> rs1 = $encoding[19:15];
Bits<5> rd = $encoding[11:7];

Execution

  • Pruned, XLEN == 64

  • Original

Bits<32> t0 = X[rs1][31:0];
Bits<32> t1 = X[rs2][31:0];
X[rd] = sext(t0 - t1, 31);
Bits<32> t0 = X[rs1][31:0];
Bits<32> t1 = X[rs2][31:0];
X[rd] = sext(t0 - t1, 31);