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| author | Richard Henderson <richard.henderson@linaro.org> | 2022-10-21 09:38:36 +1000 |
|---|---|---|
| committer | Alistair Francis <alistair.francis@wdc.com> | 2023-01-06 10:42:55 +1000 |
| commit | 9b246685b3dbbf21800e3a9a09f8bed384a1fb37 (patch) | |
| tree | 7884f6e5485c6875d57741ae0818b61aa1b7fd3b /tcg | |
| parent | 627227636127c44df0e01ab8fd9fae3f731fa8b0 (diff) | |
| download | qemu-9b246685b3dbbf21800e3a9a09f8bed384a1fb37.zip qemu-9b246685b3dbbf21800e3a9a09f8bed384a1fb37.tar.gz qemu-9b246685b3dbbf21800e3a9a09f8bed384a1fb37.tar.bz2 | |
tcg/riscv: Fix reg overlap case in tcg_out_addsub2
There was a typo using opc_addi instead of opc_add with the
two registers. While we're at it, simplify the gating test
to al == bl to improve dynamic scheduling even when the
output register does not overlap the inputs.
Reported-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20221020233836.2341671-1-richard.henderson@linaro.org>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
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, |