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tcg/ppc: Use PADDI in tcg_out_movi
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PADDI can load 34-bit immediates and 34-bit pc-relative addresses.

Reviewed-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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rth7680 committed Oct 22, 2023
1 parent 4a388c7 commit 103044e
Showing 1 changed file with 51 additions and 0 deletions.
51 changes: 51 additions & 0 deletions tcg/ppc/tcg-target.c.inc
Original file line number Diff line number Diff line change
Expand Up @@ -719,6 +719,38 @@ static bool patch_reloc(tcg_insn_unit *code_ptr, int type,
return true;
}

/* Ensure that the prefixed instruction does not cross a 64-byte boundary. */
static bool tcg_out_need_prefix_align(TCGContext *s)
{
return ((uintptr_t)s->code_ptr & 0x3f) == 0x3c;
}

static void tcg_out_prefix_align(TCGContext *s)
{
if (tcg_out_need_prefix_align(s)) {
tcg_out32(s, NOP);
}
}

static ptrdiff_t tcg_pcrel_diff_for_prefix(TCGContext *s, const void *target)
{
return tcg_pcrel_diff(s, target) - (tcg_out_need_prefix_align(s) ? 4 : 0);
}

/* Output Type 10 Prefix - Modified Load/Store Form (MLS:D) */
static void tcg_out_mls_d(TCGContext *s, tcg_insn_unit opc, unsigned rt,
unsigned ra, tcg_target_long imm, bool r)
{
tcg_insn_unit p, i;

p = OPCD(1) | (2 << 24) | (r << 20) | ((imm >> 16) & 0x3ffff);
i = opc | TAI(rt, ra, imm);

tcg_out_prefix_align(s);
tcg_out32(s, p);
tcg_out32(s, i);
}

static void tcg_out_mem_long(TCGContext *s, int opi, int opx, TCGReg rt,
TCGReg base, tcg_target_long offset);

Expand Down Expand Up @@ -1017,6 +1049,25 @@ static void tcg_out_movi_int(TCGContext *s, TCGType type, TCGReg ret,
return;
}

/*
* Load values up to 34 bits, and pc-relative addresses,
* with one prefixed insn.
*/
if (have_isa_3_10) {
if (arg == sextract64(arg, 0, 34)) {
/* pli ret,value = paddi ret,0,value,0 */
tcg_out_mls_d(s, ADDI, ret, 0, arg, 0);
return;
}

tmp = tcg_pcrel_diff_for_prefix(s, (void *)arg);
if (tmp == sextract64(tmp, 0, 34)) {
/* pla ret,value = paddi ret,0,value,1 */
tcg_out_mls_d(s, ADDI, ret, 0, tmp, 1);
return;
}
}

/* Load 32-bit immediates with two insns. Note that we've already
eliminated bare ADDIS, so we know both insns are required. */
if (TCG_TARGET_REG_BITS == 32 || arg == (int32_t)arg) {
Expand Down

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