[Qemu-devel] [PATCH 2/2] tcg/i386: remove ld/st third argument register constraint

[Aurelien Jarno]

On x86_64, remove the constraint on the third argument register which
is not needed:
 - For loads the helper arguments are env, addr, mem_idx. The addr
   value should not be in the two first argument registers as they are
   used in tcg_out_tlb_load().
 - For stores the helper arguments are env, addr, data, mem_idx.
   The addr and data values should not be in the two first argument
   registers as they are used in tcg_out_tlb_load(). The data value
   should also not be in the two first argument registers, but could
   be in the third argument register in which case it would be already
   loaded at the right location.

Signed-off-by: Aurelien Jarno <address@hidden>
---
 tcg/i386/tcg-target.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index 4c59e33..9c8f69a 100644
--- a/tcg/i386/tcg-target.c
+++ b/tcg/i386/tcg-target.c
@@ -92,7 +92,6 @@ static const int tcg_target_call_oarg_regs[] = {
 #if TCG_TARGET_REG_BITS == 64
 # define TCG_REG_L0 tcg_target_call_iarg_regs[0]
 # define TCG_REG_L1 tcg_target_call_iarg_regs[1]
-# define TCG_REG_L2 tcg_target_call_iarg_regs[2]
 #else
 # define TCG_REG_L0 TCG_REG_EAX
 # define TCG_REG_L1 TCG_REG_EDX
@@ -181,14 +180,11 @@ static int target_parse_constraint(TCGArgConstraint *ct, 
const char **pct_str)
         ct->ct |= TCG_CT_REG;
 #if TCG_TARGET_REG_BITS == 64
             tcg_regset_set32(ct->u.regs, 0, 0xffff);
-            tcg_regset_reset_reg(ct->u.regs, TCG_REG_L0);
-            tcg_regset_reset_reg(ct->u.regs, TCG_REG_L1);
-            tcg_regset_reset_reg(ct->u.regs, TCG_REG_L2);
 #else
             tcg_regset_set32(ct->u.regs, 0, 0xff);
-            tcg_regset_reset_reg(ct->u.regs, TCG_REG_L0);
-            tcg_regset_reset_reg(ct->u.regs, TCG_REG_L1);
 #endif
+        tcg_regset_reset_reg(ct->u.regs, TCG_REG_L0);
+        tcg_regset_reset_reg(ct->u.regs, TCG_REG_L1);
         break;
 
     case 'e':
-- 
1.7.10.4