[Valgrind-developers] vex: r2377: Small improvement for getIReg on MIPS when reading from r0.

[<sv...@va...>]

petarj	2012-06-07 17:52:41 +0100 (Thu, 07 Jun 2012)

  New Revision: 2377

  Log:
    Small improvement for getIReg on MIPS when reading from r0.
    
    zero register on MIPS is actually a constant, and front end should be aware of
    that. MIPS port is currently tracked as bug #270777.

  Modified files:
    trunk/priv/guest_mips_toIR.c


  Modified: trunk/priv/guest_mips_toIR.c (+7 -3)
===================================================================
--- trunk/priv/guest_mips_toIR.c	2012-06-07 09:59:53 +01:00 (rev 2376)
+++ trunk/priv/guest_mips_toIR.c	2012-06-07 17:52:41 +01:00 (rev 2377)
@@ -701,9 +701,13 @@
 
 static IRExpr *getIReg(UInt iregNo)
 {
-   IRType ty = mode64 ? Ity_I64 : Ity_I32;
-   vassert(iregNo < 32);
-   return IRExpr_Get(integerGuestRegOffset(iregNo), ty);
+   if (0 == iregNo) {
+      return mode64 ? mkU64(0x0) : mkU32(0x0);
+   } else {
+      IRType ty = mode64 ? Ity_I64 : Ity_I32;
+      vassert(iregNo < 32);
+      return IRExpr_Get(integerGuestRegOffset(iregNo), ty);
+   }
 }
 
 static IRExpr *getHI(void)