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tcg/optimize: Split out fold_brcond2

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Reduce some code duplication by folding the NE and EQ cases.

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2021-08-24 09:22:11 -07:00
parent bc47b1aa5b
commit 764d2aba08
1 changed files with 81 additions and 78 deletions
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159
tcg/optimize.c
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@ -714,6 +714,84 @@ static bool fold_andc(OptContext *ctx, TCGOp *op)
return fold_const2(ctx, op); return fold_const2(ctx, op);
} }
static bool fold_brcond2(OptContext *ctx, TCGOp *op)
{
TCGCond cond = op->args[4];
int i = do_constant_folding_cond2(&op->args[0], &op->args[2], cond);
TCGArg label = op->args[5];
int inv = 0;
if (i >= 0) {
goto do_brcond_const;
}
switch (cond) {
case TCG_COND_LT:
case TCG_COND_GE:
/*
* Simplify LT/GE comparisons vs zero to a single compare
* vs the high word of the input.
*/
if (arg_is_const(op->args[2]) && arg_info(op->args[2])->val == 0 &&
arg_is_const(op->args[3]) && arg_info(op->args[3])->val == 0) {
goto do_brcond_high;
}
break;
case TCG_COND_NE:
inv = 1;
QEMU_FALLTHROUGH;
case TCG_COND_EQ:
/*
* Simplify EQ/NE comparisons where one of the pairs
* can be simplified.
*/
i = do_constant_folding_cond(INDEX_op_brcond_i32, op->args[0],
op->args[2], cond);
switch (i ^ inv) {
case 0:
goto do_brcond_const;
case 1:
goto do_brcond_high;
}
i = do_constant_folding_cond(INDEX_op_brcond_i32, op->args[1],
op->args[3], cond);
switch (i ^ inv) {
case 0:
goto do_brcond_const;
case 1:
op->opc = INDEX_op_brcond_i32;
op->args[1] = op->args[2];
op->args[2] = cond;
op->args[3] = label;
break;
}
break;
default:
break;
do_brcond_high:
op->opc = INDEX_op_brcond_i32;
op->args[0] = op->args[1];
op->args[1] = op->args[3];
op->args[2] = cond;
op->args[3] = label;
break;
do_brcond_const:
if (i == 0) {
tcg_op_remove(ctx->tcg, op);
return true;
}
op->opc = INDEX_op_br;
op->args[0] = label;
break;
}
return false;
}
static bool fold_call(OptContext *ctx, TCGOp *op) static bool fold_call(OptContext *ctx, TCGOp *op)
{ {
TCGContext *s = ctx->tcg; TCGContext *s = ctx->tcg;
@ -1644,84 +1722,6 @@ void tcg_optimize(TCGContext *s)
} }
break; break;
case INDEX_op_brcond2_i32:
i = do_constant_folding_cond2(&op->args[0], &op->args[2],
op->args[4]);
if (i == 0) {
do_brcond_false:
tcg_op_remove(s, op);
continue;
}
if (i > 0) {
do_brcond_true:
op->opc = opc = INDEX_op_br;
op->args[0] = op->args[5];
break;
}
if ((op->args[4] == TCG_COND_LT || op->args[4] == TCG_COND_GE)
&& arg_is_const(op->args[2])
&& arg_info(op->args[2])->val == 0
&& arg_is_const(op->args[3])
&& arg_info(op->args[3])->val == 0) {
/* Simplify LT/GE comparisons vs zero to a single compare
vs the high word of the input. */
do_brcond_high:
op->opc = opc = INDEX_op_brcond_i32;
op->args[0] = op->args[1];
op->args[1] = op->args[3];
op->args[2] = op->args[4];
op->args[3] = op->args[5];
break;
}
if (op->args[4] == TCG_COND_EQ) {
/* Simplify EQ comparisons where one of the pairs
can be simplified. */
i = do_constant_folding_cond(INDEX_op_brcond_i32,
op->args[0], op->args[2],
TCG_COND_EQ);
if (i == 0) {
goto do_brcond_false;
} else if (i > 0) {
goto do_brcond_high;
}
i = do_constant_folding_cond(INDEX_op_brcond_i32,
op->args[1], op->args[3],
TCG_COND_EQ);
if (i == 0) {
goto do_brcond_false;
} else if (i < 0) {
break;
}
do_brcond_low:
memset(&ctx.temps_used, 0, sizeof(ctx.temps_used));
op->opc = INDEX_op_brcond_i32;
op->args[1] = op->args[2];
op->args[2] = op->args[4];
op->args[3] = op->args[5];
break;
}
if (op->args[4] == TCG_COND_NE) {
/* Simplify NE comparisons where one of the pairs
can be simplified. */
i = do_constant_folding_cond(INDEX_op_brcond_i32,
op->args[0], op->args[2],
TCG_COND_NE);
if (i == 0) {
goto do_brcond_high;
} else if (i > 0) {
goto do_brcond_true;
}
i = do_constant_folding_cond(INDEX_op_brcond_i32,
op->args[1], op->args[3],
TCG_COND_NE);
if (i == 0) {
goto do_brcond_low;
} else if (i > 0) {
goto do_brcond_true;
}
}
break;
default: default:
break; break;
@ -1737,6 +1737,9 @@ void tcg_optimize(TCGContext *s)
CASE_OP_32_64_VEC(andc): CASE_OP_32_64_VEC(andc):
done = fold_andc(&ctx, op); done = fold_andc(&ctx, op);
break; break;
case INDEX_op_brcond2_i32:
done = fold_brcond2(&ctx, op);
break;
CASE_OP_32_64(ctpop): CASE_OP_32_64(ctpop):
done = fold_ctpop(&ctx, op); done = fold_ctpop(&ctx, op);
break; break;