From 0a3799eadac6ad335551d4fb30328a9e6c802e8e Mon Sep 17 00:00:00 2001
From: feliam <felipe.andres.manzano@gmail.com>
Date: Wed, 9 Mar 2016 19:14:33 -0300
Subject: [PATCH] FPU control word and tags

---
 bindings/python/unicorn/x86_const.py |  4 ++-
 include/unicorn/x86.h                |  3 +-
 qemu/target-i386/unicorn.c           | 52 +++++++++++++++++++++++++---
 3 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/bindings/python/unicorn/x86_const.py b/bindings/python/unicorn/x86_const.py
index a0cf0abc..8f93c0e0 100644
--- a/bindings/python/unicorn/x86_const.py
+++ b/bindings/python/unicorn/x86_const.py
@@ -248,7 +248,9 @@ UC_X86_REG_IDTR = 242
 UC_X86_REG_GDTR = 243
 UC_X86_REG_LDTR = 244
 UC_X86_REG_TR = 245
-UC_X86_REG_ENDING = 246
+UC_X86_REG_FPTAGS = 246
+UC_X86_REG_FPCW = 247
+UC_X86_REG_ENDING = 248
 
 # X86 instructions
 
diff --git a/include/unicorn/x86.h b/include/unicorn/x86.h
index 51401eba..88559730 100644
--- a/include/unicorn/x86.h
+++ b/include/unicorn/x86.h
@@ -73,7 +73,8 @@ typedef enum uc_x86_reg {
 	UC_X86_REG_R9D, UC_X86_REG_R10D, UC_X86_REG_R11D, UC_X86_REG_R12D, UC_X86_REG_R13D,
 	UC_X86_REG_R14D, UC_X86_REG_R15D, UC_X86_REG_R8W, UC_X86_REG_R9W, UC_X86_REG_R10W,
 	UC_X86_REG_R11W, UC_X86_REG_R12W, UC_X86_REG_R13W, UC_X86_REG_R14W, UC_X86_REG_R15W,
-	UC_X86_REG_IDTR, UC_X86_REG_GDTR, UC_X86_REG_LDTR, UC_X86_REG_TR,
+	UC_X86_REG_IDTR, UC_X86_REG_GDTR, UC_X86_REG_LDTR, UC_X86_REG_TR, UC_X86_REG_FPCW,
+    UC_X86_REG_FPTAG,
 
 	UC_X86_REG_ENDING		// <-- mark the end of the list of registers
 } uc_x86_reg;
diff --git a/qemu/target-i386/unicorn.c b/qemu/target-i386/unicorn.c
index 3ab525c3..4b285f93 100644
--- a/qemu/target-i386/unicorn.c
+++ b/qemu/target-i386/unicorn.c
@@ -152,10 +152,42 @@ int x86_reg_read(struct uc_struct *uc, unsigned int regid, void *value)
         case UC_X86_REG_FPSW:
             {
                 uint16_t fpus = X86_CPU(uc, mycpu)->env.fpus;
-		fpus = fpus & ~(7<<11);
-                fpus |= (X86_CPU(uc, mycpu)->env.fpstt&7)<<11;
+        		fpus  = fpus & ~0x3800;
+                fpus |= ( X86_CPU(uc, mycpu)->env.fpstt & 0x7 ) << 11;
                 *(uint16_t*) value = fpus;
             }
+        case UC_X86_REG_FPCW:
+            *(uint16_t*) value = X86_CPU(uc, mycpu)->env.fpuc;
+            break;
+        case UC_X86_REG_FPTAG:
+            {
+                #define EXPD(fp)        (fp.l.upper & 0x7fff)
+                #define MANTD(fp)       (fp.l.lower)
+                #define MAXEXPD 0x7fff
+                int fptag, exp, i;
+                uint64_t mant;
+                CPU_LDoubleU tmp;
+                fptag = 0;
+                for (i = 7; i >= 0; i--) {
+                    fptag <<= 2;
+                    if (X86_CPU(uc, mycpu)->env.fptags[i]) {
+                        fptag |= 3;
+                    } else {
+                        tmp.d = X86_CPU(uc, mycpu)->env.fpregs[i].d;
+                        exp = EXPD(tmp);
+                        mant = MANTD(tmp);
+                        if (exp == 0 && mant == 0) {
+                            /* zero */
+                            fptag |= 1;
+                        } else if (exp == 0 || exp == MAXEXPD
+                                   || (mant & (1LL << 63)) == 0) {
+                            /* NaNs, infinity, denormal */
+                            fptag |= 2;
+                        }
+                    }
+                }
+                *(uint16_t*) value = fptag; 
+            }
             break;
     }
 
@@ -606,10 +638,22 @@ int x86_reg_write(struct uc_struct *uc, unsigned int regid, const void *value)
         case UC_X86_REG_FPSW:
             {
                 uint16_t fpus = *(uint16_t*) value;
-                X86_CPU(uc, mycpu)->env.fpus = fpus;
-                X86_CPU(uc, mycpu)->env.fpstt = (fpus>>11)&7;
+                X86_CPU(uc, mycpu)->env.fpus = fpus & ~0x3800;
+                X86_CPU(uc, mycpu)->env.fpstt = (fpus >> 11) & 0x7;
             }
             break;
+        case UC_X86_REG_FPCW:
+            *(uint16_t*) value = X86_CPU(uc, mycpu)->env.fpuc;
+            break;
+        case UC_X86_REG_FPTAG:
+            {
+                int i;
+                uint16_t fptag = *(uint16_t*) value;
+                for (i = 0; i < 8; i++) {
+                    X86_CPU(uc, mycpu)->env.fptags[i] = ((fptag & 3) == 3);
+                    fptag >>= 2;
+                }
+            }
         }
 
     switch(uc->mode) {