Hi Richard,
On 9/21/21 00:35, Richard Henderson wrote:
On 9/20/21 9:31 AM, Richard Henderson wrote:
On 9/20/21 1:04 AM, WANG Xuerui wrote:
+ } else if (TCG_TARGET_REG_BITS == 32 || offset ==
(int32_t)offset) {
+ /* long jump: +/- 2GiB */
+ tcg_out_opc_pcaddu12i(s, TCG_REG_TMP0, 0);
+ tcg_out_opc_jirl(s, link, TCG_REG_TMP0, 0);
+ ret = reloc_call(s->code_ptr - 2, arg);
+ tcg_debug_assert(ret == true);
Just inline reloc_call here, so that you can provide the correct
offsets to the pcadd and jirl instructions directly. The assert will
vanish, because you've already done the range check with "offset ==
(int32_t)offset".
Actually, don't you want offset == sextract64(offset, 0, 34), and use
pcaddu18i? Depending on the memory map of qemu, those extra bits could
make the difference in directly reaching the main executable.
Whoa, silly me, I actually didn't realize a single expected use case of
pcaddu18i until I read this, the low 2 bits are always clear so 18 is
exactly the amount of shift needed when paired with jirl!
I'll of course rework this to use pcaddu18i+jirl instead.
r~
