diff options
author | Richard Henderson <richard.henderson@linaro.org> | 2021-08-26 09:03:59 -0700 |
---|---|---|
committer | Richard Henderson <richard.henderson@linaro.org> | 2021-10-28 20:55:07 -0700 |
commit | faa2e10045ef82f4a1a24a7f69e285736143b469 (patch) | |
tree | 28093111895c2b3829c30ccb9d6d8aab2caa3a0b | |
parent | 18cf3d07a2556700895c626754937e90f8e972cf (diff) |
tcg/optimize: Stop forcing z_mask to "garbage" for 32-bit values
This "garbage" setting pre-dates the addition of the type
changing opcodes INDEX_op_ext_i32_i64, INDEX_op_extu_i32_i64,
and INDEX_op_extr{l,h}_i64_i32.
So now we have a definitive points at which to adjust z_mask
to eliminate such bits from the 32-bit operands.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
-rw-r--r-- | tcg/optimize.c | 35 |
1 files changed, 16 insertions, 19 deletions
diff --git a/tcg/optimize.c b/tcg/optimize.c index e42f5a145f..e0abf769d0 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -124,10 +124,6 @@ static void init_ts_info(OptContext *ctx, TCGTemp *ts) ti->is_const = true; ti->val = ts->val; ti->z_mask = ts->val; - if (TCG_TARGET_REG_BITS > 32 && ts->type == TCG_TYPE_I32) { - /* High bits of a 32-bit quantity are garbage. */ - ti->z_mask |= ~0xffffffffull; - } } else { ti->is_const = false; ti->z_mask = -1; @@ -192,7 +188,6 @@ static bool tcg_opt_gen_mov(OptContext *ctx, TCGOp *op, TCGArg dst, TCGArg src) TCGTemp *src_ts = arg_temp(src); TempOptInfo *di; TempOptInfo *si; - uint64_t z_mask; TCGOpcode new_op; if (ts_are_copies(dst_ts, src_ts)) { @@ -224,12 +219,7 @@ static bool tcg_opt_gen_mov(OptContext *ctx, TCGOp *op, TCGArg dst, TCGArg src) op->args[0] = dst; op->args[1] = src; - z_mask = si->z_mask; - if (TCG_TARGET_REG_BITS > 32 && new_op == INDEX_op_mov_i32) { - /* High bits of the destination are now garbage. */ - z_mask |= ~0xffffffffull; - } - di->z_mask = z_mask; + di->z_mask = si->z_mask; if (src_ts->type == dst_ts->type) { TempOptInfo *ni = ts_info(si->next_copy); @@ -247,9 +237,14 @@ static bool tcg_opt_gen_mov(OptContext *ctx, TCGOp *op, TCGArg dst, TCGArg src) static bool tcg_opt_gen_movi(OptContext *ctx, TCGOp *op, TCGArg dst, uint64_t val) { - /* Convert movi to mov with constant temp. */ - TCGTemp *tv = tcg_constant_internal(ctx->type, val); + TCGTemp *tv; + if (ctx->type == TCG_TYPE_I32) { + val = (int32_t)val; + } + + /* Convert movi to mov with constant temp. */ + tv = tcg_constant_internal(ctx->type, val); init_ts_info(ctx, tv); return tcg_opt_gen_mov(ctx, op, dst, temp_arg(tv)); } @@ -721,14 +716,16 @@ static bool fold_masks(OptContext *ctx, TCGOp *op) uint64_t z_mask = ctx->z_mask; /* - * 32-bit ops generate 32-bit results. For the result is zero test - * below, we can ignore high bits, but for further optimizations we - * need to record that the high bits contain garbage. + * 32-bit ops generate 32-bit results, which for the purpose of + * simplifying tcg are sign-extended. Certainly that's how we + * represent our constants elsewhere. Note that the bits will + * be reset properly for a 64-bit value when encountering the + * type changing opcodes. */ if (ctx->type == TCG_TYPE_I32) { - ctx->z_mask |= MAKE_64BIT_MASK(32, 32); - a_mask &= MAKE_64BIT_MASK(0, 32); - z_mask &= MAKE_64BIT_MASK(0, 32); + a_mask = (int32_t)a_mask; + z_mask = (int32_t)z_mask; + ctx->z_mask = z_mask; } if (z_mask == 0) { |