tcg/loongarch64: Fix tcg_out_movi vs some pcrel pointers

Simplify the logic for two-part, 32-bit pc-relative addresses.
Rather than assume all such fit in int32_t, do some arithmetic
and assert a result, do some arithmetic first and then check
to see if the pieces are in range.

Cc: qemu-stable@nongnu.org
Fixes: dacc51720d ("tcg/loongarch64: Implement tcg_out_mov and tcg_out_movi")
Reviewed-by: Song Gao <gaosong@loongson.cn>
Reported-by: Song Gao <gaosong@loongson.cn>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2024-06-19 05:41:13 +00:00
parent 6b4965373e
commit 521d7fb3eb

View File

@ -382,8 +382,7 @@ static void tcg_out_movi(TCGContext *s, TCGType type, TCGReg rd,
* back to the slow path.
*/
intptr_t pc_offset;
tcg_target_long val_lo, val_hi, pc_hi, offset_hi;
intptr_t src_rx, pc_offset;
tcg_target_long hi12, hi32, hi52;
/* Value fits in signed i32. */
@ -393,24 +392,23 @@ static void tcg_out_movi(TCGContext *s, TCGType type, TCGReg rd,
}
/* PC-relative cases. */
pc_offset = tcg_pcrel_diff(s, (void *)val);
if (pc_offset == sextreg(pc_offset, 0, 22) && (pc_offset & 3) == 0) {
/* Single pcaddu2i. */
tcg_out_opc_pcaddu2i(s, rd, pc_offset >> 2);
return;
src_rx = (intptr_t)tcg_splitwx_to_rx(s->code_ptr);
if ((val & 3) == 0) {
pc_offset = val - src_rx;
if (pc_offset == sextreg(pc_offset, 0, 22)) {
/* Single pcaddu2i. */
tcg_out_opc_pcaddu2i(s, rd, pc_offset >> 2);
return;
}
}
if (pc_offset == (int32_t)pc_offset) {
/* Offset within 32 bits; load with pcalau12i + ori. */
val_lo = sextreg(val, 0, 12);
val_hi = val >> 12;
pc_hi = (val - pc_offset) >> 12;
offset_hi = val_hi - pc_hi;
tcg_debug_assert(offset_hi == sextreg(offset_hi, 0, 20));
tcg_out_opc_pcalau12i(s, rd, offset_hi);
pc_offset = (val >> 12) - (src_rx >> 12);
if (pc_offset == sextreg(pc_offset, 0, 20)) {
/* Load with pcalau12i + ori. */
tcg_target_long val_lo = val & 0xfff;
tcg_out_opc_pcalau12i(s, rd, pc_offset);
if (val_lo != 0) {
tcg_out_opc_ori(s, rd, rd, val_lo & 0xfff);
tcg_out_opc_ori(s, rd, rd, val_lo);
}
return;
}