From 5e0ba156116036ba42d7ce8e361004ea20fb2d6b Mon Sep 17 00:00:00 2001 From: Sudipto Mallick Date: Sun, 11 Jul 2021 20:38:30 +0000 Subject: arm64/emit.c: fix move instructions with big immediate values Fixes #467. It assumes that the stack won't need to grow beyond 2^32 bytes. If that were to happen, we'd need another or at most two more `movk` instructions. Signed-off-by: Sudipto Mallick --- arm64/emit.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 71 insertions(+), 15 deletions(-) diff --git a/arm64/emit.c b/arm64/emit.c index eda1079..752b455 100644 --- a/arm64/emit.c +++ b/arm64/emit.c @@ -338,15 +338,21 @@ emitins(Ins *i, E *e) assert(rtype(i->arg[0]) == RSlot); rn = rname(i->to.val, Kl); s = slot(i->arg[0].val, e); - if (s <= 4095) { + if (s <= 4095) fprintf(e->f, "\tadd\t%s, x29, #%"PRIu64"\n", rn, s); - } else { + else if (s <= 65535) fprintf(e->f, "\tmov\t%s, #%"PRIu64"\n" "\tadd\t%s, x29, %s\n", rn, s, rn, rn ); - } + else + fprintf(e->f, + "\tmov\t%s, #%"PRIu64"\n" + "\tmovk\t%s, #%"PRIu64", lsl #16\n" + "\tadd\t%s, x29, %s\n", + rn, s & 0xFFFF, rn, s >> 16, rn, rn + ); break; } } @@ -435,20 +441,45 @@ arm64_emitfn(Fn *fn, FILE *out) "\tstp\tx29, x30, [sp, -16]!\n", e->frame ); - else + else if (e->frame <= 65535) fprintf(e->f, "\tmov\tx16, #%"PRIu64"\n" "\tsub\tsp, sp, x16\n" "\tstp\tx29, x30, [sp, -16]!\n", e->frame ); + else + fprintf(e->f, + "\tmov\tx16, #%"PRIu64"\n" + "\tmovk\tx16, #%"PRIu64", lsl #16\n" + "\tsub\tsp, sp, x16\n" + "\tstp\tx29, x30, [sp, -16]!\n", + e->frame & 0xFFFF, e->frame >> 16 + ); fputs("\tadd\tx29, sp, 0\n", e->f); for (o=e->frame+16, r=arm64_rclob; *r>=0; r++) - if (e->fn->reg & BIT(*r)) - fprintf(e->f, - "\tstr\t%s, [sp, %"PRIu64"]\n", - rname(*r, Kx), o -= 8 - ); + if (e->fn->reg & BIT(*r)) { + if (o <= 32760) + fprintf(e->f, + "\tstr\t%s, [sp, %"PRIu64"]\n", + rname(*r, Kx), o -= 8 + ); + else if (o <= 65535) + fprintf(e->f, + "\tmov\tx16, #%"PRIu64"\n" + "\tstr\t%s, [sp, x16]\n", + o -= 8, rname(*r, Kx) + ); + else { + o -= 8; + fprintf(e->f, + "\tmov\tx16, #%"PRIu64"\n" + "\tmovk\tx16, #%"PRIu64", lsl #16\n" + "\tstr\t%s, [sp, x16]\n", + o & 0xFFFF, o >> 16, rname(*r, Kx) + ); + } + } for (lbl=0, b=e->fn->start; b; b=b->link) { if (lbl || b->npred > 1) @@ -459,11 +490,28 @@ arm64_emitfn(Fn *fn, FILE *out) switch (b->jmp.type) { case Jret0: for (o=e->frame+16, r=arm64_rclob; *r>=0; r++) - if (e->fn->reg & BIT(*r)) - fprintf(e->f, - "\tldr\t%s, [sp, %"PRIu64"]\n", - rname(*r, Kx), o -= 8 - ); + if (e->fn->reg & BIT(*r)) { + if (o <= 32760) + fprintf(e->f, + "\tldr\t%s, [sp, %"PRIu64"]\n", + rname(*r, Kx), o -= 8 + ); + else if (o <= 65535) + fprintf(e->f, + "\tmov\tx16, #%"PRIu64"\n" + "\tldr\t%s, [sp, x16]\n", + o -= 8, rname(*r, Kx) + ); + else { + o -= 8; + fprintf(e->f, + "\tmov\tx16, #%"PRIu64"\n" + "\tmovk\tx16, #%"PRIu64", lsl #16\n" + "\tldr\t%s, [sp, x16]\n", + o & 0xFFFF, o >> 16, rname(*r, Kx) + ); + } + } o = e->frame + 16; if (e->fn->vararg) o += 192; @@ -478,13 +526,21 @@ arm64_emitfn(Fn *fn, FILE *out) "\tadd\tsp, sp, #%"PRIu64"\n", o - 16 ); - else + else if (o - 16 <= 65535) fprintf(e->f, "\tldp\tx29, x30, [sp], 16\n" "\tmov\tx16, #%"PRIu64"\n" "\tadd\tsp, sp, x16\n", o - 16 ); + else + fprintf(e->f, + "\tldp\tx29, x30, [sp], 16\n" + "\tmov\tx16, #%"PRIu64"\n" + "\tmovk\tx16, #%"PRIu64", lsl #16\n" + "\tadd\tsp, sp, x16\n", + (o - 16) & 0xFFFF, (o - 16) >> 16 + ); fprintf(e->f, "\tret\n"); break; case Jjmp: -- cgit 1.4.1