From: Julian Seward <jseward@acm.org>
Date: Tue, 3 May 2005 12:20:15 +0000 (+0000)
Subject: x86 guest: generate Iop_Neg* in the x86->IR phase.  Intent is to
X-Git-Tag: svn/VALGRIND_3_0_1^2~175
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e48f61114308fee273742273e775da057048632d;p=thirdparty%2Fvalgrind.git

x86 guest: generate Iop_Neg* in the x86->IR phase.  Intent is to
ensure that the non-shadow (real) computation done by the program will
fail if Iop_Neg* is incorrectly handled somehow.  Until this point,
Iop_Neg* is only generated by memcheck and so it will not be obvious
if it is mishandled.  IOW, this commit enhances verifiability of the
x86-IR-x86 pipeline.



git-svn-id: svn://svn.valgrind.org/vex/trunk@1159
---

diff --git a/VEX/priv/guest-x86/toIR.c b/VEX/priv/guest-x86/toIR.c
index 4e668ced9b..6d41c537ef 100644
--- a/VEX/priv/guest-x86/toIR.c
+++ b/VEX/priv/guest-x86/toIR.c
@@ -848,7 +848,7 @@ static IROp mkSizedOp ( IRType ty, IROp op8 )
            || op8 == Iop_Or8 || op8 == Iop_And8 || op8 == Iop_Xor8
            || op8 == Iop_Shl8 || op8 == Iop_Shr8 || op8 == Iop_Sar8
            || op8 == Iop_CmpEQ8 || op8 == Iop_CmpNE8
-           || op8 == Iop_Not8 );
+           || op8 == Iop_Not8 || op8 == Iop_Neg8);
    adj = ty==Ity_I8 ? 0 : (ty==Ity_I16 ? 1 : 2);
    return adj + op8;
 }
@@ -2761,7 +2761,7 @@ UInt dis_Grp3 ( UChar sorb, Int sz, UInt delta )
             dst1 = newTemp(ty);
             assign(dst0, mkU(ty,0));
             assign(src,  getIReg(sz,eregOfRM(modrm)));
-            assign(dst1, binop(mkSizedOp(ty,Iop_Sub8), mkexpr(dst0), mkexpr(src)));
+            assign(dst1, unop(mkSizedOp(ty,Iop_Neg8), mkexpr(src)));
             setFlags_DEP1_DEP2(Iop_Sub8, dst0, src, ty);
             putIReg(sz, eregOfRM(modrm), mkexpr(dst1));
             DIP("neg%c %s\n", nameISize(sz), nameIReg(sz, eregOfRM(modrm)));
@@ -2810,7 +2810,6 @@ UInt dis_Grp3 ( UChar sorb, Int sz, UInt delta )
             DIP("test%c $0x%x, %s\n", nameISize(sz), d32, dis_buf);
             break;
          }
-         /* probably OK, but awaiting test case */
          case 2: /* NOT */
             storeLE( mkexpr(addr), unop(mkSizedOp(ty,Iop_Not8), mkexpr(t1)));
             DIP("not%c %s\n", nameISize(sz), dis_buf);
@@ -2821,7 +2820,7 @@ UInt dis_Grp3 ( UChar sorb, Int sz, UInt delta )
             dst1 = newTemp(ty);
             assign(dst0, mkU(ty,0));
             assign(src,  mkexpr(t1));
-            assign(dst1, binop(mkSizedOp(ty,Iop_Sub8), mkexpr(dst0), mkexpr(src)));
+            assign(dst1, unop(mkSizedOp(ty,Iop_Neg8), mkexpr(src)));
             setFlags_DEP1_DEP2(Iop_Sub8, dst0, src, ty);
             storeLE( mkexpr(addr), mkexpr(dst1) );
             DIP("neg%c %s\n", nameISize(sz), dis_buf);
diff --git a/VEX/pub/libvex_ir.h b/VEX/pub/libvex_ir.h
index 645cacc282..4c60925784 100644
--- a/VEX/pub/libvex_ir.h
+++ b/VEX/pub/libvex_ir.h
@@ -200,8 +200,9 @@ extern void ppIRTemp ( IRTemp );
 
 typedef
    enum { 
-      /* Do not change this ordering.  The IR generators
-         rely on (eg) Iop_Add64 == IopAdd8 + 3. */
+      /* -- Do not change this ordering.  The IR generators rely on
+            (eg) Iop_Add64 == IopAdd8 + 3. -- */
+
       Iop_INVALID=0x13000,
       Iop_Add8,  Iop_Add16,  Iop_Add32,  Iop_Add64,
       Iop_Sub8,  Iop_Sub16,  Iop_Sub32,  Iop_Sub64,
@@ -218,6 +219,10 @@ typedef
       Iop_CmpNE8,  Iop_CmpNE16,  Iop_CmpNE32,  Iop_CmpNE64,
       /* Tags for unary ops */
       Iop_Not8,  Iop_Not16,  Iop_Not32,  Iop_Not64,
+      Iop_Neg8,  Iop_Neg16,  Iop_Neg32,  Iop_Neg64,
+
+      /* -- Ordering not important after here. -- */
+
       /* Widening multiplies */
       Iop_MullS8, Iop_MullS16, Iop_MullS32, Iop_MullS64,
       Iop_MullU8, Iop_MullU16, Iop_MullU32, Iop_MullU64,
@@ -229,7 +234,6 @@ typedef
          zero.  You must ensure they are never given a zero argument.
       */
 
-      /* Ordering not important after here. */
       Iop_CmpLT32S, Iop_CmpLT64S,
       Iop_CmpLE32S, Iop_CmpLE64S,
       Iop_CmpLT32U, Iop_CmpLT64U,
@@ -237,7 +241,6 @@ typedef
 
       /* As a sop to Valgrind-Memcheck, the following are useful. */
       Iop_CmpNEZ8, Iop_CmpNEZ16,  Iop_CmpNEZ32,  Iop_CmpNEZ64,
-      Iop_Neg8, Iop_Neg16, Iop_Neg32, Iop_Neg64,
 
       /* Division */
       /* TODO: clarify semantics wrt rounding, negative values, whatever */