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tcg/optimize: Split out fold_xx_to_i

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Pull the "op r, a, a => movi r, 0" optimization into a function,
and use it in the outer opcode fold functions.

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2021-08-25 13:02:00 -07:00
parent 2cfac7fa48
commit cbe42fb2f2
1 changed files with 24 additions and 17 deletions
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41
tcg/optimize.c
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@ -695,6 +695,15 @@ static bool fold_const2(OptContext *ctx, TCGOp *op)
return false; return false;
} }
/* If the binary operation has both arguments equal, fold to @i. */
static bool fold_xx_to_i(OptContext *ctx, TCGOp *op, uint64_t i)
{
if (args_are_copies(op->args[1], op->args[2])) {
return tcg_opt_gen_movi(ctx, op, op->args[0], i);
}
return false;
}
/* /*
* These outermost fold_<op> functions are sorted alphabetically. * These outermost fold_<op> functions are sorted alphabetically.
*/ */
@ -744,7 +753,11 @@ static bool fold_and(OptContext *ctx, TCGOp *op)
static bool fold_andc(OptContext *ctx, TCGOp *op) static bool fold_andc(OptContext *ctx, TCGOp *op)
{ {
return fold_const2(ctx, op); if (fold_const2(ctx, op) ||
fold_xx_to_i(ctx, op, 0)) {
return true;
}
return false;
} }
static bool fold_brcond(OptContext *ctx, TCGOp *op) static bool fold_brcond(OptContext *ctx, TCGOp *op)
@ -1224,7 +1237,11 @@ static bool fold_shift(OptContext *ctx, TCGOp *op)
static bool fold_sub(OptContext *ctx, TCGOp *op) static bool fold_sub(OptContext *ctx, TCGOp *op)
{ {
return fold_const2(ctx, op); if (fold_const2(ctx, op) ||
fold_xx_to_i(ctx, op, 0)) {
return true;
}
return false;
} }
static bool fold_sub2_i32(OptContext *ctx, TCGOp *op) static bool fold_sub2_i32(OptContext *ctx, TCGOp *op)
@ -1234,7 +1251,11 @@ static bool fold_sub2_i32(OptContext *ctx, TCGOp *op)
static bool fold_xor(OptContext *ctx, TCGOp *op) static bool fold_xor(OptContext *ctx, TCGOp *op)
{ {
return fold_const2(ctx, op); if (fold_const2(ctx, op) ||
fold_xx_to_i(ctx, op, 0)) {
return true;
}
return false;
} }
/* Propagate constants and copies, fold constant expressions. */ /* Propagate constants and copies, fold constant expressions. */
@ -1739,20 +1760,6 @@ void tcg_optimize(TCGContext *s)
break; break;
} }
/* Simplify expression for "op r, a, a => movi r, 0" cases */
switch (opc) {
CASE_OP_32_64_VEC(andc):
CASE_OP_32_64_VEC(sub):
CASE_OP_32_64_VEC(xor):
if (args_are_copies(op->args[1], op->args[2])) {
tcg_opt_gen_movi(&ctx, op, op->args[0], 0);
continue;
}
break;
default:
break;
}
/* /*
* Process each opcode. * Process each opcode.
* Sorted alphabetically by opcode as much as possible. * Sorted alphabetically by opcode as much as possible.