[v6,03/36] tcg: Allocate objects contiguously in temp_allocate_frame

Commit Message

Richard Henderson Jan. 30, 2023, 9:48 p.m. UTC

When allocating a temp to the stack frame, consider the
base type and allocate all parts at once.

Reviewed-by: Alex Bennée <[e-mail]>
Signed-off-by: Richard Henderson <[e-mail]>
---
 tcg/tcg.c | 34 ++++++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

Patch

diff --git a/tcg/tcg.c b/tcg/tcg.c
index ffddda96ed..25e92ef5d6 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -3264,11 +3264,12 @@  static bool liveness_pass_2(TCGContext *s)
 
 static void temp_allocate_frame(TCGContext *s, TCGTemp *ts)
 {
-    int size = tcg_type_size(ts->type);
-    int align;
     intptr_t off;
+    int size, align;
 
-    switch (ts->type) {
+    /* When allocating an object, look at the full type. */
+    size = tcg_type_size(ts->base_type);
+    switch (ts->base_type) {
     case TCG_TYPE_I32:
         align = 4;
         break;
@@ -3299,13 +3300,30 @@  static void temp_allocate_frame(TCGContext *s, TCGTemp *ts)
         tcg_raise_tb_overflow(s);
     }
     s->current_frame_offset = off + size;
-
-    ts->mem_offset = off;
 #if defined(__sparc__)
-    ts->mem_offset += TCG_TARGET_STACK_BIAS;
+    off += TCG_TARGET_STACK_BIAS;
 #endif
-    ts->mem_base = s->frame_temp;
-    ts->mem_allocated = 1;
+
+    /* If the object was subdivided, assign memory to all the parts. */
+    if (ts->base_type != ts->type) {
+        int part_size = tcg_type_size(ts->type);
+        int part_count = size / part_size;
+
+        /*
+         * Each part is allocated sequentially in tcg_temp_new_internal.
+         * Jump back to the first part by subtracting the current index.
+         */
+        ts -= ts->temp_subindex;
+        for (int i = 0; i < part_count; ++i) {
+            ts[i].mem_offset = off + i * part_size;
+            ts[i].mem_base = s->frame_temp;
+            ts[i].mem_allocated = 1;
+        }
+    } else {
+        ts->mem_offset = off;
+        ts->mem_base = s->frame_temp;
+        ts->mem_allocated = 1;
+    }
 }
 
 /* Assign @reg to @ts, and update reg_to_temp[]. */