[Qemu-devel] [PATCH] target-ppc: Load/Store Vector Element Storage Alignment

[Qemu-devel] [PATCH] target-ppc: Load/Store Vector Element Storage Alignment

[Tom Musta]

The Load Vector Element Indexed and Store Vector Element Indexed
instructions compute an effective address in the usual manner.
However, they truncate that address to the natural boundary.
For example, the lvewx instruction will ignore the least significant
two bits of the address and thus load the aligned word of storage.

Fix the generators for these instruction to properly perform this
truncation.

Signed-off-by: Tom Musta <tommusta@gmail.com>
---
 target-ppc/translate.c |   22 ++++++++++++++--------
 1 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index 0f8897f..aaba887 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -6783,7 +6783,7 @@ static void gen_st##name(DisasContext *ctx)                                   \
     tcg_temp_free(EA);                                                        \
 }
 
-#define GEN_VR_LVE(name, opc2, opc3)                                    \
+#define GEN_VR_LVE(name, opc2, opc3, size)                              \
 static void gen_lve##name(DisasContext *ctx)                            \
     {                                                                   \
         TCGv EA;                                                        \
@@ -6795,13 +6795,16 @@ static void gen_lve##name(DisasContext *ctx)                            \
         gen_set_access_type(ctx, ACCESS_INT);                           \
         EA = tcg_temp_new();                                            \
         gen_addr_reg_index(ctx, EA);                                    \
+        if (size > 1) {                                                 \
+            tcg_gen_andi_tl(EA, EA, ~(size - 1));                       \
+        }                                                               \
         rs = gen_avr_ptr(rS(ctx->opcode));                              \
         gen_helper_lve##name(cpu_env, rs, EA);                          \
         tcg_temp_free(EA);                                              \
         tcg_temp_free_ptr(rs);                                          \
     }
 
-#define GEN_VR_STVE(name, opc2, opc3)                                   \
+#define GEN_VR_STVE(name, opc2, opc3, size)                             \
 static void gen_stve##name(DisasContext *ctx)                           \
     {                                                                   \
         TCGv EA;                                                        \
@@ -6813,6 +6816,9 @@ static void gen_stve##name(DisasContext *ctx)                           \
         gen_set_access_type(ctx, ACCESS_INT);                           \
         EA = tcg_temp_new();                                            \
         gen_addr_reg_index(ctx, EA);                                    \
+        if (size > 1) {                                                 \
+            tcg_gen_andi_tl(EA, EA, ~(size - 1));                       \
+        }                                                               \
         rs = gen_avr_ptr(rS(ctx->opcode));                              \
         gen_helper_stve##name(cpu_env, rs, EA);                         \
         tcg_temp_free(EA);                                              \
@@ -6823,17 +6829,17 @@ GEN_VR_LDX(lvx, 0x07, 0x03);
 /* As we don't emulate the cache, lvxl is stricly equivalent to lvx */
 GEN_VR_LDX(lvxl, 0x07, 0x0B);
 
-GEN_VR_LVE(bx, 0x07, 0x00);
-GEN_VR_LVE(hx, 0x07, 0x01);
-GEN_VR_LVE(wx, 0x07, 0x02);
+GEN_VR_LVE(bx, 0x07, 0x00, 1);
+GEN_VR_LVE(hx, 0x07, 0x01, 2);
+GEN_VR_LVE(wx, 0x07, 0x02, 4);
 
 GEN_VR_STX(svx, 0x07, 0x07);
 /* As we don't emulate the cache, stvxl is stricly equivalent to stvx */
 GEN_VR_STX(svxl, 0x07, 0x0F);
 
-GEN_VR_STVE(bx, 0x07, 0x04);
-GEN_VR_STVE(hx, 0x07, 0x05);
-GEN_VR_STVE(wx, 0x07, 0x06);
+GEN_VR_STVE(bx, 0x07, 0x04, 1);
+GEN_VR_STVE(hx, 0x07, 0x05, 2);
+GEN_VR_STVE(wx, 0x07, 0x06, 4);
 
 static void gen_lvsl(DisasContext *ctx)
 {
-- 
1.7.1

Re: [Qemu-devel] [PATCH] target-ppc: Load/Store Vector Element Storage Alignment

[Alexander Graf]

On 17.11.14 21:58, Tom Musta wrote:
> The Load Vector Element Indexed and Store Vector Element Indexed
> instructions compute an effective address in the usual manner.
> However, they truncate that address to the natural boundary.
> For example, the lvewx instruction will ignore the least significant
> two bits of the address and thus load the aligned word of storage.
> 
> Fix the generators for these instruction to properly perform this
> truncation.
> 
> Signed-off-by: Tom Musta <tommusta@gmail.com>

Thanks, applied to ppc-next-2.3


Alex