From: Richard Henderson <richard.henderson@linaro.org>
Date: Sat, 22 Feb 2025 17:36:21 +0000 (-0800)
Subject: tcg: Use extract2 for cross-word 64-bit extract on 32-bit host
X-Git-Tag: v10.1.0-rc0~111^2~155
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2225fa242c5d95c5cd83bb6f8566d43dd7a00211;p=thirdparty%2Fqemu.git

tcg: Use extract2 for cross-word 64-bit extract on 32-bit host

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---

diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index fec6d678a29..f68c4f97027 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -2804,9 +2804,18 @@ void tcg_gen_extract_i64(TCGv_i64 ret, TCGv_i64 arg,
             tcg_gen_movi_i32(TCGV_HIGH(ret), 0);
             return;
         }
-        /* The field is split across two words.  One double-word
-           shift is better than two double-word shifts.  */
-        goto do_shift_and;
+
+        /* The field is split across two words. */
+        tcg_gen_extract2_i32(TCGV_LOW(ret), TCGV_LOW(arg),
+                             TCGV_HIGH(arg), ofs);
+        if (len <= 32) {
+            tcg_gen_extract_i32(TCGV_LOW(ret), TCGV_LOW(ret), 0, len);
+            tcg_gen_movi_i32(TCGV_HIGH(ret), 0);
+        } else {
+            tcg_gen_extract_i32(TCGV_HIGH(ret), TCGV_HIGH(arg),
+                                ofs, len - 32);
+        }
+        return;
     }
 
     if (TCG_TARGET_extract_valid(TCG_TYPE_I64, ofs, len)) {
@@ -2844,7 +2853,6 @@ void tcg_gen_extract_i64(TCGv_i64 ret, TCGv_i64 arg,
        so that we get ext8u, ext16u, and ext32u.  */
     switch (len) {
     case 1 ... 8: case 16: case 32:
-    do_shift_and:
         tcg_gen_shri_i64(ret, arg, ofs);
         tcg_gen_andi_i64(ret, ret, (1ull << len) - 1);
         break;