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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org
Subject: [PATCH v5 1/6] tcg/sparc: Add scratch argument to tcg_out_movi_int
Date: Sun,  6 Feb 2022 21:31:33 +1100	[thread overview]
Message-ID: <20220206103138.36105-2-richard.henderson@linaro.org> (raw)
In-Reply-To: <20220206103138.36105-1-richard.henderson@linaro.org>

This will allow us to control exactly what scratch register is
used for loading the constant.  Also, fix a theoretical problem
in recursing through tcg_out_movi, which may provide a different
value for in_prologue.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/sparc/tcg-target.c.inc | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/tcg/sparc/tcg-target.c.inc b/tcg/sparc/tcg-target.c.inc
index 0c062c60eb..8c3671f56a 100644
--- a/tcg/sparc/tcg-target.c.inc
+++ b/tcg/sparc/tcg-target.c.inc
@@ -414,7 +414,8 @@ static void tcg_out_movi_imm13(TCGContext *s, TCGReg ret, int32_t arg)
 }
 
 static void tcg_out_movi_int(TCGContext *s, TCGType type, TCGReg ret,
-                             tcg_target_long arg, bool in_prologue)
+                             tcg_target_long arg, bool in_prologue,
+                             TCGReg scratch)
 {
     tcg_target_long hi, lo = (int32_t)arg;
     tcg_target_long test, lsb;
@@ -471,22 +472,25 @@ static void tcg_out_movi_int(TCGContext *s, TCGType type, TCGReg ret,
     /* A 64-bit constant decomposed into 2 32-bit pieces.  */
     if (check_fit_i32(lo, 13)) {
         hi = (arg - lo) >> 32;
-        tcg_out_movi(s, TCG_TYPE_I32, ret, hi);
+        tcg_out_movi_int(s, TCG_TYPE_I32, ret, hi, in_prologue, scratch);
         tcg_out_arithi(s, ret, ret, 32, SHIFT_SLLX);
         tcg_out_arithi(s, ret, ret, lo, ARITH_ADD);
     } else {
+        tcg_debug_assert(scratch != TCG_REG_G0);
         hi = arg >> 32;
-        tcg_out_movi(s, TCG_TYPE_I32, ret, hi);
-        tcg_out_movi(s, TCG_TYPE_I32, TCG_REG_T2, lo);
+        tcg_out_movi_int(s, TCG_TYPE_I32, ret, hi, in_prologue, scratch);
+        tcg_out_movi_int(s, TCG_TYPE_I32, scratch, lo, in_prologue, TCG_REG_G0);
         tcg_out_arithi(s, ret, ret, 32, SHIFT_SLLX);
-        tcg_out_arith(s, ret, ret, TCG_REG_T2, ARITH_OR);
+        tcg_out_arith(s, ret, ret, scratch, ARITH_OR);
     }
 }
 
 static void tcg_out_movi(TCGContext *s, TCGType type,
                          TCGReg ret, tcg_target_long arg)
 {
-    tcg_out_movi_int(s, type, ret, arg, false);
+    /* When outputting to T2, we have no scratch available. */
+    TCGReg scratch = ret != TCG_REG_T2 ? TCG_REG_T2 : TCG_REG_G0;
+    tcg_out_movi_int(s, type, ret, arg, false, scratch);
 }
 
 static void tcg_out_ldst_rr(TCGContext *s, TCGReg data, TCGReg a1,
@@ -837,7 +841,7 @@ static void tcg_out_call_nodelay(TCGContext *s, const tcg_insn_unit *dest,
     } else {
         uintptr_t desti = (uintptr_t)dest;
         tcg_out_movi_int(s, TCG_TYPE_PTR, TCG_REG_T1,
-                         desti & ~0xfff, in_prologue);
+                         desti & ~0xfff, in_prologue, TCG_REG_O7);
         tcg_out_arithi(s, TCG_REG_O7, TCG_REG_T1, desti & 0xfff, JMPL);
     }
 }
@@ -1013,7 +1017,8 @@ static void tcg_target_qemu_prologue(TCGContext *s)
 
 #ifndef CONFIG_SOFTMMU
     if (guest_base != 0) {
-        tcg_out_movi_int(s, TCG_TYPE_PTR, TCG_GUEST_BASE_REG, guest_base, true);
+        tcg_out_movi_int(s, TCG_TYPE_PTR, TCG_GUEST_BASE_REG, guest_base,
+                         true, TCG_REG_T1);
         tcg_regset_set_reg(s->reserved_regs, TCG_GUEST_BASE_REG);
     }
 #endif
-- 
2.25.1



  reply	other threads:[~2022-02-06 10:37 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 ` Richard Henderson [this message]
2022-02-07 17:59   ` [PATCH v5 1/6] tcg/sparc: Add scratch argument to tcg_out_movi_int Peter Maydell
2022-02-07 21:48     ` Richard Henderson
2022-02-06 10:31 ` [PATCH v5 2/6] tcg/sparc: Improve code gen for shifted 32-bit constants Richard Henderson
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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