}
+/* CALLED FROM GENERATED CODE: CLEAN HELPER */
+/* Calculate both flags and value result for DAA/DAS/AAA/AAS.
+ AX value in low half of arg, OSZACP in upper half.
+ See guest-x86/toIR.c usage point for details.
+*/
+static UInt calc_parity_8bit ( UInt w32 ) {
+ UInt i;
+ UInt p = 1;
+ for (i = 0; i < 8; i++)
+ p ^= (1 & (w32 >> i));
+ return p;
+}
+UInt x86g_calculate_daa_das_aaa_aas ( UInt flags_and_AX, UInt opcode )
+{
+ UInt r_AL = (flags_and_AX >> 0) & 0xFF;
+ UInt r_AH = (flags_and_AX >> 8) & 0xFF;
+ UInt r_O = (flags_and_AX >> (16 + X86G_CC_SHIFT_O)) & 1;
+ UInt r_S = (flags_and_AX >> (16 + X86G_CC_SHIFT_S)) & 1;
+ UInt r_Z = (flags_and_AX >> (16 + X86G_CC_SHIFT_Z)) & 1;
+ UInt r_A = (flags_and_AX >> (16 + X86G_CC_SHIFT_A)) & 1;
+ UInt r_C = (flags_and_AX >> (16 + X86G_CC_SHIFT_C)) & 1;
+ UInt r_P = (flags_and_AX >> (16 + X86G_CC_SHIFT_P)) & 1;
+ UInt result = 0;
+
+ switch (opcode) {
+ case 0x27: { /* DAA */
+ UInt old_AL = r_AL;
+ UInt old_C = r_C;
+ r_C = 0;
+ if ((r_AL & 0xF) > 9 || r_A == 1) {
+ r_AL = r_AL + 6;
+ r_C = old_C;
+ if (r_AL >= 0x100) r_C = 1;
+ r_A = 1;
+ } else {
+ r_A = 0;
+ }
+ if (old_AL > 0x99 || old_C == 1) {
+ r_AL = r_AL + 0x60;
+ r_C = 1;
+ } else {
+ r_C = 0;
+ }
+ /* O is undefined. S Z and P are set according to the
+ result. */
+ r_AL &= 0xFF;
+ r_O = 0; /* let's say */
+ r_S = (r_AL & 0x80) ? 1 : 0;
+ r_Z = (r_AL == 0) ? 1 : 0;
+ r_P = calc_parity_8bit( r_AL );
+ break;
+ }
+ case 0x2F: { /* DAS */
+ UInt old_AL = r_AL;
+ UInt old_C = r_C;
+ r_C = 0;
+ if ((r_AL & 0xF) > 9 || r_A == 1) {
+ Bool borrow = r_AL < 6;
+ r_AL = r_AL - 6;
+ r_C = old_C;
+ if (borrow) r_C = 1;
+ r_A = 1;
+ } else {
+ r_A = 0;
+ }
+ if (old_AL > 0x99 || old_C == 1) {
+ r_AL = r_AL - 0x60;
+ r_C = 1;
+ } else {
+ /* Intel docs are wrong: r_C = 0; */
+ }
+ /* O is undefined. S Z and P are set according to the
+ result. */
+ r_AL &= 0xFF;
+ r_O = 0; /* let's say */
+ r_S = (r_AL & 0x80) ? 1 : 0;
+ r_Z = (r_AL == 0) ? 1 : 0;
+ r_P = calc_parity_8bit( r_AL );
+ break;
+ }
+ case 0x37: { /* AAA */
+ Bool nudge = r_AL > 0xF9;
+ if ((r_AL & 0xF) > 9 || r_A == 1) {
+ r_AL = r_AL + 6;
+ r_AH = r_AH + 1 + (nudge ? 1 : 0);
+ r_A = 1;
+ r_C = 1;
+ r_AL = r_AL & 0xF;
+ } else {
+ r_A = 0;
+ r_C = 0;
+ r_AL = r_AL & 0xF;
+ }
+ /* O S Z and P are undefined. */
+ r_O = r_S = r_Z = r_P = 0; /* let's say */
+ break;
+ }
+ case 0x3F: { /* AAS */
+ Bool nudge = r_AL < 0x06;
+ if ((r_AL & 0xF) > 9 || r_A == 1) {
+ r_AL = r_AL - 6;
+ r_AH = r_AH - 1 - (nudge ? 1 : 0);
+ r_A = 1;
+ r_C = 1;
+ r_AL = r_AL & 0xF;
+ } else {
+ r_A = 0;
+ r_C = 0;
+ r_AL = r_AL & 0xF;
+ }
+ /* O S Z and P are undefined. */
+ r_O = r_S = r_Z = r_P = 0; /* let's say */
+ break;
+ }
+ default:
+ vassert(0);
+ }
+ result = ( (r_O & 1) << (16 + X86G_CC_SHIFT_O) )
+ | ( (r_S & 1) << (16 + X86G_CC_SHIFT_S) )
+ | ( (r_Z & 1) << (16 + X86G_CC_SHIFT_Z) )
+ | ( (r_A & 1) << (16 + X86G_CC_SHIFT_A) )
+ | ( (r_C & 1) << (16 + X86G_CC_SHIFT_C) )
+ | ( (r_P & 1) << (16 + X86G_CC_SHIFT_P) )
+ | ( (r_AH & 0xFF) << 8 )
+ | ( (r_AL & 0xFF) << 0 );
+ return result;
+}
+
+
/* CALLED FROM GENERATED CODE */
/* DIRTY HELPER (non-referentially-transparent) */
/* Horrible hack. On non-x86 platforms, return 1. */
DIP("leave\n");
break;
-//-- /* ---------------- Misc weird-ass insns --------------- */
-//--
-//-- case 0x27: /* DAA */
-//-- case 0x2F: /* DAS */
-//-- t1 = newTemp(cb);
-//-- uInstr2(cb, GET, 1, ArchReg, R_AL, TempReg, t1);
-//-- /* Widen %AL to 32 bits, so it's all defined when we push it. */
-//-- uInstr1(cb, WIDEN, 4, TempReg, t1);
-//-- uWiden(cb, 1, False);
-//-- uInstr0(cb, CALLM_S, 0);
-//-- uInstr1(cb, PUSH, 4, TempReg, t1);
-//-- uInstr1(cb, CALLM, 0, Lit16,
-//-- opc == 0x27 ? VGOFF_(helper_DAA) : VGOFF_(helper_DAS) );
-//-- uFlagsRWU(cb, FlagsAC, FlagsSZACP, FlagO);
-//-- uInstr1(cb, POP, 4, TempReg, t1);
-//-- uInstr0(cb, CALLM_E, 0);
-//-- uInstr2(cb, PUT, 1, TempReg, t1, ArchReg, R_AL);
-//-- DIP(opc == 0x27 ? "daa\n" : "das\n");
-//-- break;
-//--
-//-- case 0x37: /* AAA */
-//-- case 0x3F: /* AAS */
-//-- t1 = newTemp(cb);
-//-- uInstr2(cb, GET, 2, ArchReg, R_EAX, TempReg, t1);
-//-- /* Widen %AL to 32 bits, so it's all defined when we push it. */
-//-- uInstr1(cb, WIDEN, 4, TempReg, t1);
-//-- uWiden(cb, 2, False);
-//-- uInstr0(cb, CALLM_S, 0);
-//-- uInstr1(cb, PUSH, 4, TempReg, t1);
-//-- uInstr1(cb, CALLM, 0, Lit16,
-//-- opc == 0x37 ? VGOFF_(helper_AAA) : VGOFF_(helper_AAS) );
-//-- uFlagsRWU(cb, FlagA, FlagsAC, FlagsEmpty);
-//-- uInstr1(cb, POP, 4, TempReg, t1);
-//-- uInstr0(cb, CALLM_E, 0);
-//-- uInstr2(cb, PUT, 2, TempReg, t1, ArchReg, R_EAX);
-//-- DIP(opc == 0x37 ? "aaa\n" : "aas\n");
-//-- break;
-//--
+ /* ---------------- Misc weird-ass insns --------------- */
+
+ case 0x27: /* DAA */
+ case 0x2F: /* DAS */
+ case 0x37: /* AAA */
+ case 0x3F: /* AAS */
+ /* An ugly implementation for some ugly instructions. Oh
+ well. */
+ if (sz != 4) goto decode_failure;
+ t1 = newTemp(Ity_I32);
+ t2 = newTemp(Ity_I32);
+ /* Make up a 32-bit value (t1), with the old value of AX in the
+ bottom 16 bits, and the old OSZACP bitmask in the upper 16
+ bits. */
+ assign(t1,
+ binop(Iop_16HLto32,
+ unop(Iop_32to16,
+ mk_x86g_calculate_eflags_all()),
+ getIReg(2, R_EAX)
+ ));
+ /* Call the helper fn, to get a new AX and OSZACP value, and
+ poke both back into the guest state. Also pass the helper
+ the actual opcode so it knows which of the 4 instructions it
+ is doing the computation for. */
+ vassert(opc == 0x27 || opc == 0x2F || opc == 0x37 || opc == 0x3F);
+ assign(t2,
+ mkIRExprCCall(
+ Ity_I32, 0/*regparm*/, "x86g_calculate_daa_das_aaa_aas",
+ &x86g_calculate_daa_das_aaa_aas,
+ mkIRExprVec_2( mkexpr(t1), mkU32( opc & 0xFF) )
+ ));
+ putIReg(2, R_EAX, unop(Iop_32to16, mkexpr(t2) ));
+
+ stmt( IRStmt_Put( OFFB_CC_OP, mkU32(X86G_CC_OP_COPY) ));
+ stmt( IRStmt_Put( OFFB_CC_DEP2, mkU32(0) ));
+ stmt( IRStmt_Put( OFFB_CC_DEP1,
+ binop(Iop_And32,
+ binop(Iop_Shr32, mkexpr(t2), mkU8(16)),
+ mkU32( X86G_CC_MASK_C | X86G_CC_MASK_P
+ | X86G_CC_MASK_A | X86G_CC_MASK_Z
+ | X86G_CC_MASK_S| X86G_CC_MASK_O )
+ )
+ )
+ );
+ /* Set NDEP even though it isn't used. This makes redundant-PUT
+ elimination of previous stores to this field work better. */
+ stmt( IRStmt_Put( OFFB_CC_NDEP, mkU32(0) ));
+ switch (opc) {
+ case 0x27: DIP("daa\n"); break;
+ case 0x2F: DIP("das\n"); break;
+ case 0x37: DIP("aaa\n"); break;
+ case 0x3F: DIP("aas\n"); break;
+ default: vassert(0);
+ }
+ break;
+
//-- case 0xD4: /* AAM */
//-- case 0xD5: /* AAD */
//-- d32 = getIByte(delta); delta++;
projects / thirdparty / valgrind.git / commitdiff
