Re: [Qemu-devel] [PATCH 09/18] TCG/HPPA: use stack for TCG temps

[Richard Henderson <rth@twiddle.net>]

On 06/19/2011 02:05 PM, Blue Swirl wrote:
> Use stack instead of temp_buf array in CPUState for TCG temps.
> 
> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
> ---
>  tcg/hppa/tcg-target.c |    7 +++++--
>  1 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/tcg/hppa/tcg-target.c b/tcg/hppa/tcg-target.c
> index bd40954..b900c88 100644
> --- a/tcg/hppa/tcg-target.c
> +++ b/tcg/hppa/tcg-target.c
> @@ -1612,6 +1612,11 @@ static void tcg_target_qemu_prologue(TCGContext *s)
>      /* Allocate space for the saved registers.  */
>      frame_size += ARRAY_SIZE(tcg_target_callee_save_regs) * 4;
> 
> +    /* Use the space here for the TCG temps. */
> +    tcg_set_frame(s, TCG_REG_CALL_STACK, frame_size,
> +                  CPU_TEMP_BUF_NLONGS * sizeof(long));

PA-RISC is a stack-grows-up machine.  You've placed the buffer 
above the stack pointer, and thus outside the frame.

I've tested the following, presented as a diff against your patch set
because that was easiest after having checked out your git tree.


r~
----->8----->8----->8----->8----->8----->8
From: Richard Henderson <rth@twiddle.net>
Date: Mon, 20 Jun 2011 23:24:43 +0200
Subject: [PATCH] tcg-hppa: Put the tcg save area at the right spot in the frame.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 tcg/hppa/tcg-target.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/tcg/hppa/tcg-target.c b/tcg/hppa/tcg-target.c
index 7dac3f5..95f3316 100644
--- a/tcg/hppa/tcg-target.c
+++ b/tcg/hppa/tcg-target.c
@@ -1612,9 +1612,7 @@ static void tcg_target_qemu_prologue(TCGContext *s)
     /* Allocate space for the saved registers.  */
     frame_size += ARRAY_SIZE(tcg_target_callee_save_regs) * 4;
 
-    /* Use the space here for the TCG temps. */
-    tcg_set_frame(s, TCG_REG_CALL_STACK, frame_size,
-                  TCG_TEMP_BUF_NLONGS * sizeof(long));
+    /* Allocate space for the TCG temps. */
     frame_size += TCG_TEMP_BUF_NLONGS * sizeof(long);
 
     /* Align the allocated space.  */
@@ -1634,6 +1632,10 @@ static void tcg_target_qemu_prologue(TCGContext *s)
                    TCG_REG_CALL_STACK, -frame_size + i * 4);
     }
 
+    /* Record the location of the TCG temps.  */
+    tcg_set_frame(s, TCG_REG_CALL_STACK, -frame_size + i * 4,
+                  TCG_TEMP_BUF_NLONGS * sizeof(long));
+
 #ifdef CONFIG_USE_GUEST_BASE
     if (GUEST_BASE != 0) {
         tcg_out_movi(s, TCG_TYPE_PTR, TCG_GUEST_BASE_REG, GUEST_BASE);
-- 
1.5.6.5