From 299d24a5441dafe09038a67e578d9aeb2bc3419e Mon Sep 17 00:00:00 2001
From: Michael Starzinger <michi@complang.tuwien.ac.at>
Date: Tue, 16 Sep 2008 12:42:52 +0200
Subject: [PATCH] * src/vm/jit/trap.c (trap_handle): Update executionstates PV
 register. * src/vm/jit/arm/linux/md-os.c: Further simplified signal handler.

---
 src/vm/jit/arm/linux/md-os.c | 19 +++------------
 src/vm/jit/trap.c            | 45 +++++++++++++++++++++++++++---------
 2 files changed, 37 insertions(+), 27 deletions(-)

diff --git a/src/vm/jit/arm/linux/md-os.c b/src/vm/jit/arm/linux/md-os.c
index 40a199c84..1b1142e5a 100644
--- a/src/vm/jit/arm/linux/md-os.c
+++ b/src/vm/jit/arm/linux/md-os.c
@@ -127,7 +127,7 @@ void md_signal_handler_sigill(int sig, siginfo_t *siginfo, void *_p)
 
 	void* pv  = (void*) _sc->arm_ip;
 	void* sp  = (void*) _sc->arm_sp;
-	u1*   ra  = (void*) _sc->arm_lr; // The RA is correct for leaf methods.
+	void* ra  = (void*) _sc->arm_lr; // The RA is correct for leaf methods.
 	void* xpc = (void*) _sc->arm_pc;
 
 	// Get the exception-throwing instruction.
@@ -158,24 +158,11 @@ void md_signal_handler_sigill(int sig, siginfo_t *siginfo, void *_p)
 		/* The XPC is the RA minus 4, because the RA points to the
 		   instruction after the call. */
 
-		xpc = ra - 4;
+		xpc = (void*) (((uintptr_t) ra) - 4);
 	}
 
 	// Handle the trap.
-	void* p = trap_handle(type, val, pv, sp, ra, xpc, _p);
-
-	if (type == TRAP_COMPILER) {
-		if (p != NULL) {
-			_sc->arm_ip = (uintptr_t) p; // set REG_PV correctly
-		}
-		else {
-			/* Get and set the PV from the parent Java method. */
-
-			pv = md_codegen_get_pv_from_pc(ra);
-
-			_sc->arm_ip = (uintptr_t) pv;
-		}
-	}
+	trap_handle(type, val, pv, sp, ra, xpc, _p);
 }
 
 
diff --git a/src/vm/jit/trap.c b/src/vm/jit/trap.c
index 4278f62ff..e4d507c32 100644
--- a/src/vm/jit/trap.c
+++ b/src/vm/jit/trap.c
@@ -29,6 +29,7 @@
 
 /* Include machine dependent trap stuff. */
 
+#include "md.h"
 #include "md-trap.h"
 
 #include "mm/memory.h"
@@ -240,26 +241,48 @@ void* trap_handle(int type, intptr_t val, void *pv, void *sp, void *ra, void *xp
 	stacktrace_stackframeinfo_remove(&sfi);
 
 #if defined(__ARM__) || defined(__I386__) || defined(__X86_64__)
-	/* Update execution state and write it back to the current context. */
+	/* Update execution state and set registers. */
 	/* AFTER: removing stackframeinfo */
 
-	if (type == TRAP_COMPILER) {
-		if (p == NULL) {
-			java_handle_t *e = exceptions_get_and_clear_exception();
-			es.intregs[REG_ITMP1_XPTR] = (uintptr_t) LLNI_DIRECT(e);
-			es.intregs[REG_ITMP2_XPC]  = (uintptr_t) xpc;
-			es.pc                      = (uint8_t *) (uintptr_t) asm_handle_exception;
-		} else {
-			es.pc                      = (uint8_t *) (uintptr_t) p;
+	switch (type) {
+	case TRAP_COMPILER:
+		// The default case for a compiler trap is to jump directly to
+		// the newly compiled method.
+
+		if (p != NULL) {
+			es.pc = (uint8_t *) (uintptr_t) p;
+			es.pv = (uint8_t *) (uintptr_t) p;
+			break;
 		}
-	} else {
+
+		// In case of an exception during JIT compilation, we fetch
+		// the exception here and proceed with exception handling.
+
+		java_handle_t *e = exceptions_get_and_clear_exception();
+		assert(e != NULL);
+
+		// Get and set the PV from the parent Java method.
+
+		es.pv = md_codegen_get_pv_from_pc(ra);
+
+		// XXX: Make the code below a fall-through to default case!
+
+		es.intregs[REG_ITMP1_XPTR] = (uintptr_t) LLNI_DIRECT(e);
+		es.intregs[REG_ITMP2_XPC]  = (uintptr_t) xpc;
+		es.pc                      = (uint8_t *) (uintptr_t) asm_handle_exception;
+
+		break;
+
+	default:
 		if (p != NULL) {
-			es.intregs[REG_ITMP1_XPTR] = (uintptr_t) p;
+			es.intregs[REG_ITMP1_XPTR] = (uintptr_t) LLNI_DIRECT(p);
 			es.intregs[REG_ITMP2_XPC]  = (uintptr_t) xpc;
 			es.pc                      = (uint8_t *) (uintptr_t) asm_handle_exception;
 		}
 	}
 
+	/* Write back execution state to current context. */
+
 	md_executionstate_write(&es, context);
 #endif
 
-- 
2.25.1