Skip to contentSkip to conversation

target-xtensa: fix cross-page jumps/calls at the end of TB

PATCH In review Max Filippov 1 participant 2 messages May 20, 2014

lore
Share & tools
lore
#0 lore raw

PATCH 1/1 target-xtensa: fix cross-page jumps/calls at the end of TB

Move cross-page jump check to gen_jump_slot and use tb->pc instead of dc->pc to check for cross-page jumps.
When TB ends at the page boundary dc->pc points to the next page allowing chaining to TBs in it.

---
 target-xtensa/translate.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)
target-xtensa/translate.c +1 -7
index 764cee9..d93d0a3 100644
@@ -401,7 +401,7 @@ static void gen_jump_slot(DisasContext *dc, TCGv dest, int slot)
     if (dc->singlestep_enabled) {
         gen_exception(dc, EXCP_DEBUG);
     } else {
-        if (slot >= 0) {
+        if (slot >= 0 && ((dc->tb->pc ^ dest) & TARGET_PAGE_MASK) == 0) {
             tcg_gen_goto_tb(slot);
             tcg_gen_exit_tb((uintptr_t)dc->tb + slot);
         } else {
@@ -419,9 +419,6 @@ static void gen_jump(DisasContext *dc, TCGv dest)
 static void gen_jumpi(DisasContext *dc, uint32_t dest, int slot)
 {
     TCGv_i32 tmp = tcg_const_i32(dest);
-    if (((dc->pc ^ dest) & TARGET_PAGE_MASK) != 0) {
-        slot = -1;
-    }
     gen_jump_slot(dc, tmp, slot);
     tcg_temp_free(tmp);
 }
@@ -447,9 +444,6 @@ static void gen_callw(DisasContext *dc, int callinc, TCGv_i32 dest)
 static void gen_callwi(DisasContext *dc, int callinc, uint32_t dest, int slot)
 {
     TCGv_i32 tmp = tcg_const_i32(dest);
-    if (((dc->pc ^ dest) & TARGET_PAGE_MASK) != 0) {
-        slot = -1;
-    }
     gen_callw_slot(dc, callinc, tmp, slot);
     tcg_temp_free(tmp);
 }
Signature · 1 line
1.8.1.4
#1 lore raw
Quoted 15 lines · Max Filippov

Move cross-page jump check to gen_jump_slot and use tb->pc instead of dc->pc to check for cross-page jumps.
When TB ends at the page boundary dc->pc points to the next page allowing chaining to TBs in it.

---
 target-xtensa/translate.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)
target-xtensa/translate.c +0 -0
index 764cee9..d93d0a3 100644

target-xtensa/translate.c static void gen_jump_slot(DisasContext *dc, TCGv dest, int slot) · line 404

Quoted 5 lines
target-xtensa/translate.c +1 -1
@@ -401,7 +401,7 @@ static void gen_jump_slot(DisasContext *dc, TCGv dest, int slot)
     if (dc->singlestep_enabled) {
         gen_exception(dc, EXCP_DEBUG);
     } else {
-        if (slot >= 0) {
+        if (slot >= 0 && ((dc->tb->pc ^ dest) & TARGET_PAGE_MASK) == 0) {

Ugh, complete nonsense, please ignore. ):

Signature · 2 lines
Thanks.
-- Max