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authorBrian Paul <brianp@vmware.com>2009-09-10 12:44:28 -0600
committerBrian Paul <brianp@vmware.com>2009-09-10 12:45:27 -0600
commitd78a19612173eda51b93818a16a947201a785f3f (patch)
tree992fc82acbee789de3c104a040b00397fc71bd35
parentc5f8594aebac4b8ba972d09ab18dabd9cc47c8e9 (diff)
tgsi: use new tgsi_call_record to handle execution mask stacks
This fixes some issues when "return"ing from nested loops/conditionals.
-rw-r--r--src/gallium/auxiliary/tgsi/tgsi_exec.c44
-rw-r--r--src/gallium/auxiliary/tgsi/tgsi_exec.h13
2 files changed, 43 insertions, 14 deletions
diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.c b/src/gallium/auxiliary/tgsi/tgsi_exec.c
index 60ffa188df..c79c56debd 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.c
@@ -2756,19 +2756,32 @@ exec_instruction(
if (mach->ExecMask) {
/* do the call */
- /* push the Cond, Loop, Cont stacks */
+ /* First, record the depths of the execution stacks.
+ * This is important for deeply nested/looped return statements.
+ * We have to unwind the stacks by the correct amount. For a
+ * real code generator, we could determine the number of entries
+ * to pop off each stack with simple static analysis and avoid
+ * implementing this data structure at run time.
+ */
+ mach->CallStack[mach->CallStackTop].CondStackTop = mach->CondStackTop;
+ mach->CallStack[mach->CallStackTop].LoopStackTop = mach->LoopStackTop;
+ mach->CallStack[mach->CallStackTop].ContStackTop = mach->ContStackTop;
+ /* note that PC was already incremented above */
+ mach->CallStack[mach->CallStackTop].ReturnAddr = *pc;
+
+ mach->CallStackTop++;
+
+ /* Second, push the Cond, Loop, Cont, Func stacks */
assert(mach->CondStackTop < TGSI_EXEC_MAX_COND_NESTING);
mach->CondStack[mach->CondStackTop++] = mach->CondMask;
assert(mach->LoopStackTop < TGSI_EXEC_MAX_LOOP_NESTING);
mach->LoopStack[mach->LoopStackTop++] = mach->LoopMask;
assert(mach->ContStackTop < TGSI_EXEC_MAX_LOOP_NESTING);
mach->ContStack[mach->ContStackTop++] = mach->ContMask;
-
assert(mach->FuncStackTop < TGSI_EXEC_MAX_CALL_NESTING);
mach->FuncStack[mach->FuncStackTop++] = mach->FuncMask;
- /* note that PC was already incremented above */
- mach->CallStack[mach->CallStackTop++] = *pc;
+ /* Finally, jump to the subroutine */
*pc = inst->InstructionExtLabel.Label;
}
break;
@@ -2785,18 +2798,24 @@ exec_instruction(
*pc = -1;
return;
}
- *pc = mach->CallStack[--mach->CallStackTop];
- /* pop the Cond, Loop, Cont stacks */
- assert(mach->CondStackTop > 0);
- mach->CondMask = mach->CondStack[--mach->CondStackTop];
- assert(mach->LoopStackTop > 0);
- mach->LoopMask = mach->LoopStack[--mach->LoopStackTop];
- assert(mach->ContStackTop > 0);
- mach->ContMask = mach->ContStack[--mach->ContStackTop];
+ assert(mach->CallStackTop > 0);
+ mach->CallStackTop--;
+
+ mach->CondStackTop = mach->CallStack[mach->CallStackTop].CondStackTop;
+ mach->CondMask = mach->CondStack[mach->CondStackTop];
+
+ mach->LoopStackTop = mach->CallStack[mach->CallStackTop].LoopStackTop;
+ mach->LoopMask = mach->LoopStack[mach->LoopStackTop];
+
+ mach->ContStackTop = mach->CallStack[mach->CallStackTop].ContStackTop;
+ mach->ContMask = mach->ContStack[mach->ContStackTop];
+
assert(mach->FuncStackTop > 0);
mach->FuncMask = mach->FuncStack[--mach->FuncStackTop];
+ *pc = mach->CallStack[mach->CallStackTop].ReturnAddr;
+
UPDATE_EXEC_MASK(mach);
}
break;
@@ -3245,7 +3264,6 @@ tgsi_exec_machine_run( struct tgsi_exec_machine *mach )
mach->FuncMask = 0xf;
mach->ExecMask = 0xf;
- mach->CondStackTop = 0; /* temporarily subvert this assertion */
assert(mach->CondStackTop == 0);
assert(mach->LoopStackTop == 0);
assert(mach->ContStackTop == 0);
diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.h b/src/gallium/auxiliary/tgsi/tgsi_exec.h
index 3baa94dbdd..c72f76809d 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.h
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.h
@@ -186,6 +186,17 @@ struct tgsi_exec_labels
*/
#define TGSI_EXEC_MAX_CONST_BUFFER 4096
+
+/** function call/activation record */
+struct tgsi_call_record
+{
+ uint CondStackTop;
+ uint LoopStackTop;
+ uint ContStackTop;
+ uint ReturnAddr;
+};
+
+
/**
* Run-time virtual machine state for executing TGSI shader.
*/
@@ -249,7 +260,7 @@ struct tgsi_exec_machine
int FuncStackTop;
/** Function call stack for saving/restoring the program counter */
- uint CallStack[TGSI_EXEC_MAX_CALL_NESTING];
+ struct tgsi_call_record CallStack[TGSI_EXEC_MAX_CALL_NESTING];
int CallStackTop;
struct tgsi_full_instruction *Instructions;