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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, "Philippe Mathieu-Daudé" <f4bug@amsat.org>
Subject: [PATCH v5 2/6] tcg/sparc: Improve code gen for shifted 32-bit constants
Date: Sun,  6 Feb 2022 21:31:34 +1100	[thread overview]
Message-ID: <20220206103138.36105-3-richard.henderson@linaro.org> (raw)
In-Reply-To: <20220206103138.36105-1-richard.henderson@linaro.org>

We had code for checking for 13 and 21-bit shifted constants,
but we can do better and allow 32-bit shifted constants.
This is still 2 insns shorter than the full 64-bit sequence.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/sparc/tcg-target.c.inc | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/tcg/sparc/tcg-target.c.inc b/tcg/sparc/tcg-target.c.inc
index 8c3671f56a..f9afb1bffc 100644
--- a/tcg/sparc/tcg-target.c.inc
+++ b/tcg/sparc/tcg-target.c.inc
@@ -456,17 +456,17 @@ static void tcg_out_movi_int(TCGContext *s, TCGType type, TCGReg ret,
         return;
     }
 
-    /* A 21-bit constant, shifted.  */
+    /* A 32-bit constant, shifted.  */
     lsb = ctz64(arg);
     test = (tcg_target_long)arg >> lsb;
-    if (check_fit_tl(test, 13)) {
-        tcg_out_movi_imm13(s, ret, test);
-        tcg_out_arithi(s, ret, ret, lsb, SHIFT_SLLX);
-        return;
-    } else if (lsb > 10 && test == extract64(test, 0, 21)) {
+    if (lsb > 10 && test == extract64(test, 0, 21)) {
         tcg_out_sethi(s, ret, test << 10);
         tcg_out_arithi(s, ret, ret, lsb - 10, SHIFT_SLLX);
         return;
+    } else if (test == (uint32_t)test || test == (int32_t)test) {
+        tcg_out_movi_int(s, TCG_TYPE_I64, ret, test, in_prologue, scratch);
+        tcg_out_arithi(s, ret, ret, lsb, SHIFT_SLLX);
+        return;
     }
 
     /* A 64-bit constant decomposed into 2 32-bit pieces.  */
-- 
2.25.1



  parent reply	other threads:[~2022-02-06 10:44 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-06 10:31 [PATCH v5 0/6] tcg/sparc: Unaligned access for user-only Richard Henderson
2022-02-06 10:31 ` [PATCH v5 1/6] tcg/sparc: Add scratch argument to tcg_out_movi_int Richard Henderson
2022-02-07 17:59   ` Peter Maydell
2022-02-07 21:48     ` Richard Henderson
2022-02-06 10:31 ` Richard Henderson [this message]
2022-02-06 10:31 ` [PATCH v5 3/6] tcg/sparc: Convert patch_reloc to return bool Richard Henderson
2022-02-06 10:45   ` Peter Maydell
2022-02-06 10:31 ` [PATCH v5 4/6] tcg/sparc: Use the constant pool for 64-bit constants Richard Henderson
2022-02-06 10:31 ` [PATCH v5 5/6] tcg/sparc: Add tcg_out_jmpl_const for better tail calls Richard Henderson
2022-02-06 10:31 ` [PATCH v5 6/6] tcg/sparc: Support unaligned access for user-only Richard Henderson
2022-02-07 18:30   ` Peter Maydell

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