[Guile-commits] 01/01: Fix JIT register state tracking for use of SP or FP as temp

[Andy Wingo]

wingo pushed a commit to branch master
in repository guile.

commit afced398d43f8dece0c5a3da7e3323d91ff6b9a3
Author: Andy Wingo <address@hidden>
Date:   Tue Oct 9 08:51:41 2018 +0200

    Fix JIT register state tracking for use of SP or FP as temp
    
    * libguile/jit.c (record_gpr_clobber): If we clobber SP or FP, clear the
      appropriate register state bits.  Only exercised for 32-bit targets in
      practice!
      (emit_alloc_frame, emit_push_frame): Fix a couple places where we were
      failing to track the register state correctly.
      (compile_umul): Remove a needless register state flush, nowthat
      qmulr_u has a wrapper that tracks this for us.
---
 libguile/jit.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/libguile/jit.c b/libguile/jit.c
index dcd3560..c69ea92 100644
--- a/libguile/jit.c
+++ b/libguile/jit.c
@@ -369,6 +369,11 @@ record_gpr_clobber (scm_jit_state *j, jit_gpr_t r)
 {
   if (j->sp_cache_gpr == r)
     clear_register_state (j, SP_CACHE_GPR);
+
+  if (r == SP)
+    clear_register_state (j, SP_IN_REGISTER);
+  else if (r == FP)
+    clear_register_state (j, FP_IN_REGISTER);
 }
 
 static void
@@ -756,6 +761,7 @@ emit_alloc_frame (scm_jit_state *j, jit_gpr_t t, uint32_t 
nlocals)
 {
   ASSERT_HAS_REGISTER_STATE (FP_IN_REGISTER);
   emit_subtract_stack_slots (j, SP, FP, nlocals);
+  set_register_state (j, SP_IN_REGISTER);
   emit_alloc_frame_for_sp (j, t);
 }
 
@@ -834,6 +840,7 @@ emit_push_frame (scm_jit_state *j, uint32_t proc_slot, 
uint32_t nlocals,
 
   emit_reload_fp (j);
   emit_subtract_stack_slots (j, FP, FP, proc_slot);
+  set_register_state (j, FP_IN_REGISTER);
   continuation = emit_store_mra (j, FP, t);
   emit_store_vra (j, FP, t, vra);
   emit_store_prev_fp_offset (j, FP, t, proc_slot);
@@ -2704,7 +2711,6 @@ compile_umul (scm_jit_state *j, uint8_t dst, uint8_t a, 
uint8_t b)
   emit_addr (j, T1, T1, T3_OR_FP); /* Add high results, throw away overflow */
   emit_qmulr_u (j, T0, T2, T0, T2); /* Low A times low B */
   emit_addr (j, T1, T1, T2);        /* Add high result of low product */
-  clear_register_state (j, SP_CACHE_FPR | SP_CACHE_GPR);
   emit_sp_set_u64 (j, dst, T0, T1);
 #endif
 }