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[Qemu-devel] [PATCH 1/4] tcg-arm: Implement deposit for armv7
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PATCH 1/4] tcg-arm: Implement deposit for armv7 |
Date: |
Tue, 5 Mar 2013 07:56:35 -0800 |
We have BFI and BFC available for implementing it.
Signed-off-by: Richard Henderson <address@hidden>
---
tcg/arm/tcg-target.c | 36 ++++++++++++++++++++++++++++++++++++
tcg/arm/tcg-target.h | 5 ++++-
2 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c
index 94c6ca4..3422bd7 100644
--- a/tcg/arm/tcg-target.c
+++ b/tcg/arm/tcg-target.c
@@ -644,6 +644,35 @@ static inline void tcg_out_bswap32(TCGContext *s, int
cond, int rd, int rn)
}
}
+bool tcg_target_deposit_i32_value(int ofs, int len)
+{
+ /* ??? Without bfi, we could improve over generic code by combining
+ the right-shift from a non-zero ofs with the orr. We do run into
+ problems when rd == rs, and the mask generated from ofs+len don't
+ fit into an immediate. We would have to be careful not to pessimize
+ wrt the optimizations performed on the expanded code. */
+ return use_armv7_instructions;
+}
+
+static inline void tcg_out_deposit(TCGContext *s, int cond, TCGReg rd,
+ TCGArg a1, int ofs, int len, bool const_a1)
+{
+ if (const_a1) {
+ uint32_t mask = (2u << (len - 1)) - 1;
+ a1 &= mask;
+ if (a1 == 0) {
+ /* bfi becomes bfc with rn == 15. */
+ a1 = 15;
+ } else {
+ tcg_out_movi32(s, cond, TCG_REG_R8, a1);
+ a1 = TCG_REG_R8;
+ }
+ }
+ /* bfi/bfc */
+ tcg_out32(s, 0x07c00010 | (cond << 28) | (rd << 12) | a1
+ | (ofs << 7) | ((ofs + len - 1) << 16));
+}
+
static inline void tcg_out_ld32_12(TCGContext *s, int cond,
int rd, int rn, tcg_target_long im)
{
@@ -1773,6 +1802,11 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode
opc,
tcg_out_ext16u(s, COND_AL, args[0], args[1]);
break;
+ case INDEX_op_deposit_i32:
+ tcg_out_deposit(s, COND_AL, args[0], args[2],
+ args[3], args[4], const_args[2]);
+ break;
+
default:
tcg_abort();
}
@@ -1858,6 +1892,8 @@ static const TCGTargetOpDef arm_op_defs[] = {
{ INDEX_op_ext16s_i32, { "r", "r" } },
{ INDEX_op_ext16u_i32, { "r", "r" } },
+ { INDEX_op_deposit_i32, { "r", "0", "ri" } },
+
{ -1 },
};
diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h
index b6eed1f..cb89419 100644
--- a/tcg/arm/tcg-target.h
+++ b/tcg/arm/tcg-target.h
@@ -73,10 +73,13 @@ typedef enum {
#define TCG_TARGET_HAS_eqv_i32 0
#define TCG_TARGET_HAS_nand_i32 0
#define TCG_TARGET_HAS_nor_i32 0
-#define TCG_TARGET_HAS_deposit_i32 0
+#define TCG_TARGET_HAS_deposit_i32 1
#define TCG_TARGET_HAS_movcond_i32 1
#define TCG_TARGET_HAS_muls2_i32 1
+extern bool tcg_target_deposit_i32_value(int ofs, int len);
+#define TCG_TARGET_deposit_i32_valid tcg_target_deposit_i32_value
+
enum {
TCG_AREG0 = TCG_REG_R6,
};
--
1.8.1.2