qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: luis.pires@eldorado.org.br, alex.bennee@linaro.org
Subject: [PATCH v3 43/48] tcg/optimize: Stop forcing z_mask to "garbage" for 32-bit values
Date: Thu, 21 Oct 2021 14:05:34 -0700	[thread overview]
Message-ID: <20211021210539.825582-44-richard.henderson@linaro.org> (raw)
In-Reply-To: <20211021210539.825582-1-richard.henderson@linaro.org>

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.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/optimize.c | 35 ++++++++++++++++-------------------
 1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/tcg/optimize.c b/tcg/optimize.c
index dc7744d41a..89117dd420 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));
 }
@@ -708,14 +703,16 @@ 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) {
-- 
2.25.1



  parent reply	other threads:[~2021-10-21 21:39 UTC|newest]

Thread overview: 108+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-21 21:04 [PATCH v3 00/48] tcg: optimize redundant sign extensions Richard Henderson
2021-10-21 21:04 ` [PATCH v3 01/48] tcg/optimize: Rename "mask" to "z_mask" Richard Henderson
2021-10-21 21:04 ` [PATCH v3 02/48] tcg/optimize: Split out OptContext Richard Henderson
2021-10-22 14:53   ` Philippe Mathieu-Daudé
2021-10-21 21:04 ` [PATCH v3 03/48] tcg/optimize: Remove do_default label Richard Henderson
2021-10-22 15:12   ` Philippe Mathieu-Daudé
2021-10-21 21:04 ` [PATCH v3 04/48] tcg/optimize: Change tcg_opt_gen_{mov, movi} interface Richard Henderson
2021-10-21 21:04 ` [PATCH v3 05/48] tcg/optimize: Move prev_mb into OptContext Richard Henderson
2021-10-22 15:13   ` Philippe Mathieu-Daudé
2021-10-21 21:04 ` [PATCH v3 06/48] tcg/optimize: Split out init_arguments Richard Henderson
2021-10-21 21:04 ` [PATCH v3 07/48] tcg/optimize: Split out copy_propagate Richard Henderson
2021-10-21 21:04 ` [PATCH v3 08/48] tcg/optimize: Split out fold_call Richard Henderson
2021-10-21 21:05 ` [PATCH v3 09/48] tcg/optimize: Drop nb_oargs, nb_iargs locals Richard Henderson
2021-10-21 21:05 ` [PATCH v3 10/48] tcg/optimize: Change fail return for do_constant_folding_cond* Richard Henderson
2021-10-22 13:53   ` Philippe Mathieu-Daudé
2021-10-21 21:05 ` [PATCH v3 11/48] tcg/optimize: Return true from tcg_opt_gen_{mov, movi} Richard Henderson
2021-10-26 15:13   ` [PATCH v3 11/48] tcg/optimize: Return true from tcg_opt_gen_{mov,movi} Alex Bennée
2021-10-21 21:05 ` [PATCH v3 12/48] tcg/optimize: Split out finish_folding Richard Henderson
2021-10-26 15:16   ` Alex Bennée
2021-10-21 21:05 ` [PATCH v3 13/48] tcg/optimize: Use a boolean to avoid a mass of continues Richard Henderson
2021-10-26 15:17   ` Alex Bennée
2021-10-21 21:05 ` [PATCH v3 14/48] tcg/optimize: Split out fold_mb, fold_qemu_{ld,st} Richard Henderson
2021-10-22 13:56   ` Philippe Mathieu-Daudé
2021-10-21 21:05 ` [PATCH v3 15/48] tcg/optimize: Split out fold_const{1,2} Richard Henderson
2021-10-26 15:19   ` Alex Bennée
2021-10-21 21:05 ` [PATCH v3 16/48] tcg/optimize: Split out fold_setcond2 Richard Henderson
2021-10-26 15:31   ` Alex Bennée
2021-10-21 21:05 ` [PATCH v3 17/48] tcg/optimize: Split out fold_brcond2 Richard Henderson
2021-10-22 17:26   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 18/48] tcg/optimize: Split out fold_brcond Richard Henderson
2021-10-22 13:58   ` Philippe Mathieu-Daudé
2021-10-21 21:05 ` [PATCH v3 19/48] tcg/optimize: Split out fold_setcond Richard Henderson
2021-10-22 13:59   ` Philippe Mathieu-Daudé
2021-10-21 21:05 ` [PATCH v3 20/48] tcg/optimize: Split out fold_mulu2_i32 Richard Henderson
2021-10-22 14:00   ` Philippe Mathieu-Daudé
2021-10-22 17:32   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 21/48] tcg/optimize: Split out fold_addsub2_i32 Richard Henderson
2021-10-22 14:01   ` Philippe Mathieu-Daudé
2021-10-22 17:33   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 22/48] tcg/optimize: Split out fold_movcond Richard Henderson
2021-10-22 14:05   ` Philippe Mathieu-Daudé
2021-10-22 17:34   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 23/48] tcg/optimize: Split out fold_extract2 Richard Henderson
2021-10-22 14:07   ` Philippe Mathieu-Daudé
2021-10-22 17:34   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 24/48] tcg/optimize: Split out fold_extract, fold_sextract Richard Henderson
2021-10-22 14:08   ` Philippe Mathieu-Daudé
2021-10-22 17:34   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 25/48] tcg/optimize: Split out fold_deposit Richard Henderson
2021-10-22 14:09   ` Philippe Mathieu-Daudé
2021-10-22 17:35   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 26/48] tcg/optimize: Split out fold_count_zeros Richard Henderson
2021-10-22 14:10   ` Philippe Mathieu-Daudé
2021-10-22 17:35   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 27/48] tcg/optimize: Split out fold_bswap Richard Henderson
2021-10-22 17:36   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 28/48] tcg/optimize: Split out fold_dup, fold_dup2 Richard Henderson
2021-10-22 14:12   ` Philippe Mathieu-Daudé
2021-10-22 17:36   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 29/48] tcg/optimize: Split out fold_mov Richard Henderson
2021-10-22 17:39   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 30/48] tcg/optimize: Split out fold_xx_to_i Richard Henderson
2021-10-22 21:04   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 31/48] tcg/optimize: Split out fold_xx_to_x Richard Henderson
2021-10-22 21:04   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 32/48] tcg/optimize: Split out fold_xi_to_i Richard Henderson
2021-10-22 21:17   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 33/48] tcg/optimize: Add type to OptContext Richard Henderson
2021-10-22 22:11   ` Luis Fernando Fujita Pires
2021-10-23 18:25     ` Richard Henderson
2021-10-21 21:05 ` [PATCH v3 34/48] tcg/optimize: Split out fold_to_not Richard Henderson
2021-10-25 14:17   ` Luis Fernando Fujita Pires
2021-10-25 17:31     ` Richard Henderson
2021-10-25 18:13       ` Luis Fernando Fujita Pires
2021-10-25 18:35         ` Richard Henderson
2021-10-21 21:05 ` [PATCH v3 35/48] tcg/optimize: Split out fold_sub_to_neg Richard Henderson
2021-10-25 14:17   ` Luis Fernando Fujita Pires
2021-10-21 21:05 ` [PATCH v3 36/48] tcg/optimize: Split out fold_xi_to_x Richard Henderson
2021-10-25 14:26   ` Luis Fernando Fujita Pires
2021-10-25 17:46     ` Richard Henderson
2021-10-21 21:05 ` [PATCH v3 37/48] tcg/optimize: Split out fold_ix_to_i Richard Henderson
2021-10-25 14:26   ` Luis Fernando Fujita Pires
2021-10-26 19:11   ` Philippe Mathieu-Daudé
2021-10-21 21:05 ` [PATCH v3 38/48] tcg/optimize: Split out fold_masks Richard Henderson
2021-10-26 15:32   ` Alex Bennée
2021-10-26 18:50     ` Richard Henderson
2021-10-21 21:05 ` [PATCH v3 39/48] tcg/optimize: Expand fold_mulu2_i32 to all 4-arg multiplies Richard Henderson
2021-10-22 14:16   ` Philippe Mathieu-Daudé
2021-10-21 21:05 ` [PATCH v3 40/48] tcg/optimize: Expand fold_addsub2_i32 to 64-bit ops Richard Henderson
2021-10-26 16:21   ` Alex Bennée
2021-10-21 21:05 ` [PATCH v3 41/48] tcg/optimize: Sink commutative operand swapping into fold functions Richard Henderson
2021-10-26 16:27   ` Alex Bennée
2021-10-26 19:33     ` Richard Henderson
2021-10-27 13:22       ` Alex Bennée
2021-10-21 21:05 ` [PATCH v3 42/48] tcg/optimize: Add more simplifications for orc Richard Henderson
2021-10-26 16:22   ` Alex Bennée
2021-10-21 21:05 ` Richard Henderson [this message]
2021-10-26 16:35   ` [PATCH v3 43/48] tcg/optimize: Stop forcing z_mask to "garbage" for 32-bit values Alex Bennée
2021-10-21 21:05 ` [PATCH v3 44/48] tcg/optimize: Optimize sign extensions Richard Henderson
2021-10-26 16:34   ` Alex Bennée
2021-10-21 21:05 ` [PATCH v3 45/48] tcg/optimize: Propagate sign info for logical operations Richard Henderson
2021-10-26 16:35   ` Alex Bennée
2021-10-21 21:05 ` [PATCH v3 46/48] tcg/optimize: Propagate sign info for setcond Richard Henderson
2021-10-26 16:36   ` Alex Bennée
2021-10-21 21:05 ` [PATCH v3 47/48] tcg/optimize: Propagate sign info for bit counting Richard Henderson
2021-10-26 16:36   ` Alex Bennée
2021-10-21 21:05 ` [PATCH v3 48/48] tcg/optimize: Propagate sign info for shifting Richard Henderson
2021-10-26 16:37   ` Alex Bennée

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211021210539.825582-44-richard.henderson@linaro.org \
    --to=richard.henderson@linaro.org \
    --cc=alex.bennee@linaro.org \
    --cc=luis.pires@eldorado.org.br \
    --cc=qemu-devel@nongnu.org \
    --subject='Re: [PATCH v3 43/48] tcg/optimize: Stop forcing z_mask to "garbage" for 32-bit values' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).