diff mbox series

[7/8] target/mips: Support TCG_TARGET_SIGNED_ADDR32

Message ID 20211010174401.141339-8-richard.henderson@linaro.org
State New
Headers show
Series tcg: support 32-bit guest addresses as signed | expand

Commit Message

Richard Henderson Oct. 10, 2021, 5:44 p.m. UTC
All 32-bit mips operations sign-extend the output, so we are easily
able to keep TCG_TYPE_I32 values sign-extended in host registers.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 tcg/mips/tcg-target-sa32.h |  8 ++++++++
 tcg/mips/tcg-target.c.inc  | 13 +++----------
 2 files changed, 11 insertions(+), 10 deletions(-)

-- 
2.25.1

Comments

WANG Xuerui Oct. 11, 2021, 4:20 a.m. UTC | #1
Hi Richard,

On 2021/10/11 01:44, Richard Henderson wrote:
> All 32-bit mips operations sign-extend the output, so we are easily

> able to keep TCG_TYPE_I32 values sign-extended in host registers.

>

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

> ---

>  tcg/mips/tcg-target-sa32.h |  8 ++++++++

>  tcg/mips/tcg-target.c.inc  | 13 +++----------

>  2 files changed, 11 insertions(+), 10 deletions(-)

>

> diff --git a/tcg/mips/tcg-target-sa32.h b/tcg/mips/tcg-target-sa32.h

> index cb185b1526..51255e7cba 100644

> --- a/tcg/mips/tcg-target-sa32.h

> +++ b/tcg/mips/tcg-target-sa32.h

> @@ -1 +1,9 @@

> +/*

> + * Do not set TCG_TARGET_SIGNED_ADDR32 for mips32;

> + * TCG expects this to only be set for 64-bit hosts.

> + */

> +#ifdef __mips64

> +#define TCG_TARGET_SIGNED_ADDR32 1

> +#else

>  #define TCG_TARGET_SIGNED_ADDR32 0

> +#endif

It looks like we never want to set TCG_TARGET_SIGNED_ADDR32 on 32-bit
hosts; maybe a compile-time assert could be added somewhere for
statically guaranteeing this?
> diff --git a/tcg/mips/tcg-target.c.inc b/tcg/mips/tcg-target.c.inc

> index d8f6914f03..cc3b4d5b90 100644

> --- a/tcg/mips/tcg-target.c.inc

> +++ b/tcg/mips/tcg-target.c.inc

> @@ -1161,20 +1161,13 @@ static void tcg_out_tlb_load(TCGContext *s, TCGReg base, TCGReg addrl,

>          tcg_out_ld(s, TCG_TYPE_I32, TCG_TMP0, TCG_TMP3, cmp_off + LO_OFF);

>          tcg_out_movi(s, TCG_TYPE_I32, TCG_TMP1, mask);

>      } else {

> -        tcg_out_ldst(s, (TARGET_LONG_BITS == 64 ? OPC_LD

> -                         : TCG_TARGET_REG_BITS == 64 ? OPC_LWU : OPC_LW),

> -                     TCG_TMP0, TCG_TMP3, cmp_off);

> +        tcg_out_ld(s, TCG_TYPE_TL, TCG_TMP0, TCG_TMP3, cmp_off);

>          tcg_out_movi(s, TCG_TYPE_TL, TCG_TMP1, mask);

>          /* No second compare is required here;

>             load the tlb addend for the fast path.  */

>          tcg_out_ld(s, TCG_TYPE_PTR, TCG_TMP2, TCG_TMP3, add_off);

>      }

>  

> -    /* Zero extend a 32-bit guest address for a 64-bit host. */

> -    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS) {

> -        tcg_out_ext32u(s, base, addrl);

> -        addrl = base;

> -    }

>      tcg_out_opc_reg(s, OPC_AND, TCG_TMP1, TCG_TMP1, addrl);

>  

>      label_ptr[0] = s->code_ptr;

> @@ -1456,7 +1449,7 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, bool is_64)

>                          data_regl, data_regh, addr_regl, addr_regh,

>                          s->code_ptr, label_ptr);

>  #else

> -    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS) {

> +    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS && !guest_base_signed_addr32) {

Is there precedent of extracting predicates like this into some header
for reuse? However I agree that the current expression conveys enough
meaning without being overly complicated.
>          tcg_out_ext32u(s, base, addr_regl);

>          addr_regl = base;

>      }

> @@ -1559,7 +1552,7 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, bool is_64)

>                          s->code_ptr, label_ptr);

>  #else

>      base = TCG_REG_A0;

> -    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS) {

> +    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS && !guest_base_signed_addr32) {

>          tcg_out_ext32u(s, base, addr_regl);

>          addr_regl = base;

>      }
Richard Henderson Oct. 13, 2021, 10:24 p.m. UTC | #2
On 10/10/21 9:20 PM, WANG Xuerui wrote:
>> +++ b/tcg/mips/tcg-target-sa32.h

>> @@ -1 +1,9 @@

>> +/*

>> + * Do not set TCG_TARGET_SIGNED_ADDR32 for mips32;

>> + * TCG expects this to only be set for 64-bit hosts.

>> + */

>> +#ifdef __mips64

>> +#define TCG_TARGET_SIGNED_ADDR32 1

>> +#else

>>   #define TCG_TARGET_SIGNED_ADDR32 0

>> +#endif

> It looks like we never want to set TCG_TARGET_SIGNED_ADDR32 on 32-bit

> hosts; maybe a compile-time assert could be added somewhere for

> statically guaranteeing this?


I've placed a build-time assert in tcg/tcg.c.

>> -    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS) {

>> +    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS && !guest_base_signed_addr32) {

> Is there precedent of extracting predicates like this into some header

> for reuse? However I agree that the current expression conveys enough

> meaning without being overly complicated.


Depends on the expected scope of the predicate, I guess.

If it's private to tcg-target.c.inc, I'd put it in tcg.c.
If it's private to tcg in general, I'd put it in tcg-internal.h.
Beyond that, I guess it depends.

For this, I don't know what I'd call it that isn't more verbose than the expression itself.

r~
diff mbox series

Patch

diff --git a/tcg/mips/tcg-target-sa32.h b/tcg/mips/tcg-target-sa32.h
index cb185b1526..51255e7cba 100644
--- a/tcg/mips/tcg-target-sa32.h
+++ b/tcg/mips/tcg-target-sa32.h
@@ -1 +1,9 @@ 
+/*
+ * Do not set TCG_TARGET_SIGNED_ADDR32 for mips32;
+ * TCG expects this to only be set for 64-bit hosts.
+ */
+#ifdef __mips64
+#define TCG_TARGET_SIGNED_ADDR32 1
+#else
 #define TCG_TARGET_SIGNED_ADDR32 0
+#endif
diff --git a/tcg/mips/tcg-target.c.inc b/tcg/mips/tcg-target.c.inc
index d8f6914f03..cc3b4d5b90 100644
--- a/tcg/mips/tcg-target.c.inc
+++ b/tcg/mips/tcg-target.c.inc
@@ -1161,20 +1161,13 @@  static void tcg_out_tlb_load(TCGContext *s, TCGReg base, TCGReg addrl,
         tcg_out_ld(s, TCG_TYPE_I32, TCG_TMP0, TCG_TMP3, cmp_off + LO_OFF);
         tcg_out_movi(s, TCG_TYPE_I32, TCG_TMP1, mask);
     } else {
-        tcg_out_ldst(s, (TARGET_LONG_BITS == 64 ? OPC_LD
-                         : TCG_TARGET_REG_BITS == 64 ? OPC_LWU : OPC_LW),
-                     TCG_TMP0, TCG_TMP3, cmp_off);
+        tcg_out_ld(s, TCG_TYPE_TL, TCG_TMP0, TCG_TMP3, cmp_off);
         tcg_out_movi(s, TCG_TYPE_TL, TCG_TMP1, mask);
         /* No second compare is required here;
            load the tlb addend for the fast path.  */
         tcg_out_ld(s, TCG_TYPE_PTR, TCG_TMP2, TCG_TMP3, add_off);
     }
 
-    /* Zero extend a 32-bit guest address for a 64-bit host. */
-    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS) {
-        tcg_out_ext32u(s, base, addrl);
-        addrl = base;
-    }
     tcg_out_opc_reg(s, OPC_AND, TCG_TMP1, TCG_TMP1, addrl);
 
     label_ptr[0] = s->code_ptr;
@@ -1456,7 +1449,7 @@  static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, bool is_64)
                         data_regl, data_regh, addr_regl, addr_regh,
                         s->code_ptr, label_ptr);
 #else
-    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS) {
+    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS && !guest_base_signed_addr32) {
         tcg_out_ext32u(s, base, addr_regl);
         addr_regl = base;
     }
@@ -1559,7 +1552,7 @@  static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, bool is_64)
                         s->code_ptr, label_ptr);
 #else
     base = TCG_REG_A0;
-    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS) {
+    if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS && !guest_base_signed_addr32) {
         tcg_out_ext32u(s, base, addr_regl);
         addr_regl = base;
     }