X86: Change the meaning of the sext and zext width operand, and make sext set zext if the sign bit is 0.

--HG--
extra : convert_revision : 08bd7b4ff183038c016612d04ac73b20a255d141

src/arch/x86/isa/insts/general_purpose/data_conversion/sign_extension.py

@@ -55,7 +55,7 @@
 
 microcode = '''
 def macroop CDQE_R {
-    sext reg, reg, "env.dataSize << 2"
+    sexti reg, reg, "env.dataSize << 2 - 1"
 };
 
 def macroop CQO_R_R {

src/arch/x86/isa/insts/general_purpose/data_conversion/translate.py

@@ -55,7 +55,7 @@
 
 microcode = '''
 def macroop XLAT {
-    zext t1, rax, 8
+    zexti t1, rax, 7
     # Here, t1 can be used directly. The value of al is supposed to be treated
     # as unsigned. Since we zero extended it from 8 bits above and the address
     # size has to be at least 16 bits, t1 will not be sign extended.

src/arch/x86/isa/insts/general_purpose/data_transfer/move.py

@@ -111,48 +111,48 @@ def macroop MOV_P_I {
 #
 
 def macroop MOVSXD_R_R {
-    sext reg, regm, 32
+    sexti reg, regm, 31
 };
 
 def macroop MOVSXD_R_M {
     ld t1, seg, sib, disp, dataSize=4
-    sext reg, t1, 32
+    sexti reg, t1, 31
 };
 
 def macroop MOVSXD_R_P {
     rdip t7
     ld t1, seg, riprel, disp, dataSize=4
-    sext reg, t1, 32
+    sexti reg, t1, 31
 };
 
 def macroop MOVSX_B_R_R {
-    sext reg, regm, 8
+    sexti reg, regm, 7
 };
 
 def macroop MOVSX_B_R_M {
     ld reg, seg, sib, disp, dataSize=1
-    sext reg, reg, 8
+    sexti reg, reg, 7
 };
 
 def macroop MOVSX_B_R_P {
     rdip t7
     ld reg, seg, riprel, disp, dataSize=1
-    sext reg, reg, 8
+    sexti reg, reg, 7
 };
 
 def macroop MOVSX_W_R_R {
-    sext reg, regm, 16
+    sexti reg, regm, 15
 };
 
 def macroop MOVSX_W_R_M {
     ld reg, seg, sib, disp, dataSize=2
-    sext reg, reg, 16
+    sexti reg, reg, 15
 };
 
 def macroop MOVSX_W_R_P {
     rdip t7
     ld reg, seg, riprel, disp, dataSize=2
-    sext reg, reg, 16
+    sexti reg, reg, 15
 };
 
 #
@@ -160,33 +160,33 @@ def macroop MOVSX_W_R_P {
 #
 
 def macroop MOVZX_B_R_R {
-    zext reg, regm, 8
+    zexti reg, regm, 7
 };
 
 def macroop MOVZX_B_R_M {
     ld t1, seg, sib, disp, dataSize=1
-    zext reg, t1, 8
+    zexti reg, t1, 7
 };
 
 def macroop MOVZX_B_R_P {
     rdip t7
     ld t1, seg, riprel, disp, dataSize=1
-    zext reg, t1, 8
+    zexti reg, t1, 7
 };
 
 def macroop MOVZX_W_R_R {
-    zext reg, regm, 16
+    zexti reg, regm, 15
 };
 
 def macroop MOVZX_W_R_M {
     ld t1, seg, sib, disp, dataSize=2
-    zext reg, t1, 16
+    zexti reg, t1, 15
 };
 
 def macroop MOVZX_W_R_P {
     rdip t7
     ld t1, seg, riprel, disp, dataSize=2
-    zext reg, t1, 16
+    zexti reg, t1, 15
 };
 '''
 #let {{

src/arch/x86/isa/insts/general_purpose/data_transfer/stack_operations.py

@@ -162,9 +162,9 @@ def macroop ENTER_I_I {
 
     # Pull the different components out of the immediate
     limm t1, imm
-    zext t2, t1, 16, dataSize=2
+    zexti t2, t1, 15, dataSize=2
     srl t1, t1, 16
-    zext t1, t1, 6
+    zexti t1, t1, 5
     # t1 is now the masked nesting level, and t2 is the amount of storage.
 
     # Push rbp.

src/arch/x86/isa/insts/general_purpose/input_output/general_io.py

@@ -62,7 +62,7 @@ microcode = '''
 
     def macroop IN_R_R {
         limm t1, "IntAddrPrefixIO"
-        zext t2, regm, 16, dataSize=2
+        zexti t2, regm, 15, dataSize=2
         ld reg, intseg, [1, t1, t2], addressSize=8
     };
 
@@ -74,7 +74,7 @@ microcode = '''
 
     def macroop OUT_R_R {
         limm t1, "IntAddrPrefixIO"
-        zext t2, reg, 16, dataSize=2
+        zexti t2, reg, 15, dataSize=2
         st regm, intseg, [1, t1, t2], addressSize=8
     };
 '''

src/arch/x86/isa/insts/general_purpose/input_output/string_io.py

@@ -62,7 +62,7 @@ def macroop INS_M_R {
     mov t3, t3, t4, flags=(nCEZF,), dataSize=asz
 
     limm t1, "IntAddrPrefixIO"
-    zext t2, reg, 16, dataSize=2
+    zexti t2, reg, 15, dataSize=2
 
     ld t6, intseg, [1, t1, t2], addressSize=8
     st t6, es, [1, t0, rdi]
@@ -78,7 +78,7 @@ def macroop INS_E_M_R {
     mov t3, t3, t4, flags=(nCEZF,), dataSize=asz
 
     limm t1, "IntAddrPrefixIO"
-    zext t2, reg, 16, dataSize=2
+    zexti t2, reg, 15, dataSize=2
 
 topOfLoop:
     ld t6, intseg, [1, t1, t2], addressSize=8
@@ -98,7 +98,7 @@ def macroop OUTS_R_M {
     mov t3, t3, t4, flags=(nCEZF,), dataSize=asz
 
     limm t1, "IntAddrPrefixIO"
-    zext t2, reg, 16, dataSize=2
+    zexti t2, reg, 15, dataSize=2
 
     ld t6, ds, [1, t0, rsi]
     st t6, intseg, [1, t1, t2], addressSize=8
@@ -114,7 +114,7 @@ def macroop OUTS_E_R_M {
     mov t3, t3, t4, flags=(nCEZF,), dataSize=asz
 
     limm t1, "IntAddrPrefixIO"
-    zext t2, reg, 16, dataSize=2
+    zexti t2, reg, 15, dataSize=2
 
 topOfLoop:
     ld t6, ds, [1, t0, rsi]

src/arch/x86/isa/microops/regop.isa

@@ -318,7 +318,7 @@ let {{
 
             # If there's something optional to do with flags, generate
             # a version without it and fix up this version to use it.
-            if flag_code is not "" or cond_check is not "true":
+            if flag_code != "" or cond_check != "true":
                 self.buildCppClasses(name, Name, suffix,
                         code, "", "true", else_code)
                 suffix = "Flags" + suffix
@@ -866,12 +866,22 @@ let {{
     class Sext(RegOp):
         code = '''
             IntReg val = psrc1;
-            int sign_bit = bits(val, imm8-1, imm8-1);
-            uint64_t maskVal = mask(imm8);
+            // Mask the bit position so that it wraps.
+            int bitPos = op2 & (dataSize * 8 - 1);
+            int sign_bit = bits(val, bitPos, bitPos);
+            uint64_t maskVal = mask(bitPos+1);
             val = sign_bit ? (val | ~maskVal) : (val & maskVal);
             DestReg = merge(DestReg, val, dataSize);
             '''
+        flag_code = '''
+            if (!sign_bit)
+                ccFlagBits = ccFlagBits &
+                    ~(ext & (CFBit | ECFBit | ZFBit | EZFBit));
+            else
+                ccFlagBits = ccFlagBits |
+                    (ext & (CFBit | ECFBit | ZFBit | EZFBit));
+            '''
 
     class Zext(RegOp):
-        code = 'DestReg = bits(psrc1, imm8-1, 0);'
+        code = 'DestReg = bits(psrc1, op2, 0);'
 }};