diff options
Diffstat (limited to 'tcg')
| -rw-r--r-- | tcg/riscv/tcg-target.c.inc | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/tcg/riscv/tcg-target.c.inc b/tcg/riscv/tcg-target.c.inc index 1911978..2a84c57 100644 --- a/tcg/riscv/tcg-target.c.inc +++ b/tcg/riscv/tcg-target.c.inc @@ -700,9 +700,15 @@ static void tcg_out_addsub2(TCGContext *s, if (cbl) { tcg_out_opc_imm(s, opc_addi, rl, al, bl); tcg_out_opc_imm(s, OPC_SLTIU, TCG_REG_TMP0, rl, bl); - } else if (rl == al && rl == bl) { + } else if (al == bl) { + /* + * If the input regs overlap, this is a simple doubling + * and carry-out is the input msb. This special case is + * required when the output reg overlaps the input, + * but we might as well use it always. + */ tcg_out_opc_imm(s, OPC_SLTI, TCG_REG_TMP0, al, 0); - tcg_out_opc_reg(s, opc_addi, rl, al, bl); + tcg_out_opc_reg(s, opc_add, rl, al, al); } else { tcg_out_opc_reg(s, opc_add, rl, al, bl); tcg_out_opc_reg(s, OPC_SLTU, TCG_REG_TMP0, |