Fixed tracing.

Added possibility to unfollow jump (#7).
Added possibility to return from multiple locations in code (related to unfollow).
Added more tests.
Moved some functions from X86Context to Context.

src/app/test/asmjit_test_x86.cpp

@@ -14,6 +14,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <setjmp.h>
 
 using namespace asmjit;
 
@@ -2601,14 +2602,14 @@ struct X86Test_CallMisc3 : public X86Test {
 };
 
 // ============================================================================
-// [X86Test_ConstPoolBase]
+// [X86Test_MiscConstPool]
 // ============================================================================
 
-struct X86Test_ConstPoolBase : public X86Test {
-  X86Test_ConstPoolBase() : X86Test("[ConstPool] Base") {}
+struct X86Test_MiscConstPool : public X86Test {
+  X86Test_MiscConstPool() : X86Test("[Misc] ConstPool") {}
 
   static void add(PodVector<X86Test*>& tests) {
-    tests.append(new X86Test_ConstPoolBase());
+    tests.append(new X86Test_MiscConstPool());
   }
 
   virtual void compile(X86Compiler& c) {
@@ -2642,6 +2643,156 @@ struct X86Test_ConstPoolBase : public X86Test {
   }
 };
 
+// ============================================================================
+// [X86Test_MiscMultiRet]
+// ============================================================================
+
+struct X86Test_MiscMultiRet : public X86Test {
+  X86Test_MiscMultiRet() : X86Test("[Misc] MultiRet") {}
+
+  static void add(PodVector<X86Test*>& tests) {
+    tests.append(new X86Test_MiscMultiRet());
+  }
+
+  virtual void compile(X86Compiler& c) {
+    c.addFunc(kFuncConvHost, FuncBuilder3<int, int, int, int>());
+
+    X86GpVar op(c, kVarTypeInt32, "op");
+    X86GpVar a(c, kVarTypeInt32, "a");
+    X86GpVar b(c, kVarTypeInt32, "b");
+
+    Label L_Zero(c);
+    Label L_Add(c);
+    Label L_Sub(c);
+    Label L_Mul(c);
+    Label L_Div(c);
+
+    c.setArg(0, op);
+    c.setArg(1, a);
+    c.setArg(2, b);
+
+    c.cmp(op, 0);
+    c.jz(L_Add);
+
+    c.cmp(op, 1);
+    c.jz(L_Sub);
+
+    c.cmp(op, 2);
+    c.jz(L_Mul);
+
+    c.cmp(op, 3);
+    c.jz(L_Div);
+
+    c.bind(L_Zero);
+    c.xor_(a, a);
+    c.ret(a);
+
+    c.bind(L_Add);
+    c.add(a, b);
+    c.ret(a);
+
+    c.bind(L_Sub);
+    c.sub(a, b);
+    c.ret(a);
+
+    c.bind(L_Mul);
+    c.imul(a, b);
+    c.ret(a);
+
+    c.bind(L_Div);
+    c.cmp(b, 0);
+    c.jz(L_Zero);
+
+    X86GpVar zero(c, kVarTypeInt32, "zero");
+    c.xor_(zero, zero);
+    c.idiv(zero, a, b);
+    c.ret(a);
+
+    c.endFunc();
+  }
+
+  virtual bool run(void* _func, StringBuilder& result, StringBuilder& expect) {
+    typedef int (*Func)(int, int, int);
+
+    Func func = asmjit_cast<Func>(_func);
+
+    int a = 44;
+    int b = 3;
+
+    int r0 = func(0, a, b);
+    int r1 = func(1, a, b);
+    int r2 = func(2, a, b);
+    int r3 = func(3, a, b);
+    int e0 = a + b;
+    int e1 = a - b;
+    int e2 = a * b;
+    int e3 = a / b;
+
+    result.setFormat("ret={%d %d %d %d}", r0, r1, r2, r3);
+    expect.setFormat("ret={%d %d %d %d}", e0, e1, e2, e3);
+
+    return result.eq(expect);
+}
+};
+
+// ============================================================================
+// [X86Test_MiscUnfollow]
+// ============================================================================
+
+// Global (I didn't find better way to really test this).
+static jmp_buf globalJmpBuf;
+
+struct X86Test_MiscUnfollow : public X86Test {
+  X86Test_MiscUnfollow() : X86Test("[Misc] Unfollow") {}
+
+  static void add(PodVector<X86Test*>& tests) {
+    tests.append(new X86Test_MiscUnfollow());
+  }
+
+  virtual void compile(X86Compiler& c) {
+    c.addFunc(kFuncConvHost, FuncBuilder2<void, int, void*>());
+
+    X86GpVar a(c, kVarTypeInt32);
+    X86GpVar b(c, kVarTypeIntPtr);
+
+    Label tramp(c);
+
+    c.setArg(0, a);
+    c.setArg(1, b);
+
+    c.cmp(a, 0);
+    c.jz(tramp);
+
+    c.ret(a);
+
+    c.bind(tramp);
+    c.unfollow().jmp(b);
+
+    c.endFunc();
+  }
+
+  virtual bool run(void* _func, StringBuilder& result, StringBuilder& expect) {
+    typedef int (*Func)(int, void*);
+
+    Func func = asmjit_cast<Func>(_func);
+
+    int resultRet = 0;
+    int expectRet = 1;
+
+    if (!setjmp(globalJmpBuf))
+      resultRet = func(0, (void*)handler);
+    else
+      resultRet = 1;
+
+    result.setFormat("ret={%d}", resultRet);
+    expect.setFormat("ret={%d}", expectRet);
+
+    return resultRet == expectRet;
+  }
+
+  static void handler() { longjmp(globalJmpBuf, 1); }
+};
+
 // ============================================================================
 // [X86TestSuite]
 // ============================================================================
@@ -2730,7 +2881,11 @@ X86TestSuite::X86TestSuite() :
   ADD_TEST(X86Test_CallMisc1);
   ADD_TEST(X86Test_CallMisc2);
   ADD_TEST(X86Test_CallMisc3);
-  ADD_TEST(X86Test_ConstPoolBase);
+
+  // Misc.
+  ADD_TEST(X86Test_MiscConstPool);
+  ADD_TEST(X86Test_MiscUnfollow);
+  ADD_TEST(X86Test_MiscMultiRet);
 }
 
 X86TestSuite::~X86TestSuite() {

src/asmjit/base/assembler.h

@@ -68,7 +68,12 @@ ASMJIT_ENUM(InstOptions) {
   kInstOptionTaken = 0x00000004,
 
   //! Condition is unlikely to be taken.
-  kInstOptionNotTaken = 0x00000008
+  kInstOptionNotTaken = 0x00000008,
+
+  //! Don't follow the jump (Compiler-only).
+  //!
+  //! Prevents following the jump during compilation.
+  kInstOptionUnfollow = 0x00000010
 };
 
 // ============================================================================

src/asmjit/base/compiler.cpp

@@ -192,24 +192,26 @@ static ASMJIT_INLINE void BaseCompiler_nodeRemoved(Compiler* self, Node* node_)
     JumpNode* node = static_cast<JumpNode*>(node_);
     TargetNode* target = node->getTarget();
 
-    // Disconnect.
-    JumpNode** pPrev = &target->_from;
-    for (;;) {
-      ASMJIT_ASSERT(*pPrev != NULL);
-      JumpNode* current = *pPrev;
+    if (target != NULL) {
+      // Disconnect.
+      JumpNode** pPrev = &target->_from;
+      for (;;) {
+        ASMJIT_ASSERT(*pPrev != NULL);
+        JumpNode* current = *pPrev;
 
-      if (current == NULL)
-        break;
+        if (current == NULL)
+          break;
 
-      if (current == node) {
-        *pPrev = node->_jumpNext;
-        break;
+        if (current == node) {
+          *pPrev = node->_jumpNext;
+          break;
+        }
+
+        pPrev = &current->_jumpNext;
       }
 
-      pPrev = &current->_jumpNext;
+      target->subNumRefs();
     }
-
-    target->subNumRefs();
   }
 }
 

src/asmjit/base/context.cpp

@@ -48,6 +48,7 @@ void Context::reset(bool releaseMemory) {
   _stop = NULL;
 
   _unreachableList.reset();
+  _returningList.reset();
   _jccList.reset();
   _contextVd.reset(releaseMemory);
 
@@ -277,7 +278,7 @@ Error Context::removeUnreachableCode() {
 
   while (link != NULL) {
     Node* node = link->getValue();
-    if (node != NULL && node->getPrev() != NULL) {
+    if (node != NULL && node->getPrev() != NULL && node != stop) {
       // Locate all unreachable nodes.
       Node* first = node;
       do {
@@ -292,8 +293,10 @@ Error Context::removeUnreachableCode() {
         node = first;
         do {
           Node* next = node->getNext();
-          if (!node->isInformative() && node->getType() != kNodeTypeAlign)
+          if (!node->isInformative() && node->getType() != kNodeTypeAlign) {
+            ASMJIT_TLOG("[%05d] Unreachable\n", node->getFlowId());
             compiler->removeNode(node);
+          }
           node = next;
         } while (node != end);
       }
@@ -321,23 +324,27 @@ struct LivenessTarget {
 };
 
 Error Context::livenessAnalysis() {
-  FuncNode* func = getFunc();
-  JumpNode* from = NULL;
-
-  Node* node = func->getEnd();
   uint32_t bLen = static_cast<uint32_t>(
     ((_contextVd.getLength() + VarBits::kEntityBits - 1) / VarBits::kEntityBits));
 
-  LivenessTarget* ltCur = NULL;
-  LivenessTarget* ltUnused = NULL;
-
-  size_t varMapToVaListOffset = _varMapToVaListOffset;
-
   // No variables.
   if (bLen == 0)
     return kErrorOk;
 
+  FuncNode* func = getFunc();
+  JumpNode* from = NULL;
+
+  LivenessTarget* ltCur = NULL;
+  LivenessTarget* ltUnused = NULL;
+
+  PodList<Node*>::Link* retPtr = _returningList.getFirst();
+  ASMJIT_ASSERT(retPtr != NULL);
+
+  Node* node = retPtr->getValue();
+
+  size_t varMapToVaListOffset = _varMapToVaListOffset;
   VarBits* bCur = newBits(bLen);
+
   if (bCur == NULL)
     goto _NoMemory;
 
@@ -491,6 +498,13 @@ _OnDone:
 
     goto _OnJumpNext;
   }
+
+  retPtr = retPtr->getNext();
+  if (retPtr != NULL) {
+    node = retPtr->getValue();
+    goto _OnVisit;
+  }
+
   return kErrorOk;
 
 _NoMemory:

src/asmjit/base/context_p.h

@@ -160,12 +160,53 @@ struct Context {
   virtual Error fetch() = 0;
 
   // --------------------------------------------------------------------------
-  // [RemoveUnreachableCode]
+  // [Unreachable Code]
   // --------------------------------------------------------------------------
 
+  //! Add unreachable-flow data to the unreachable flow list.
+  ASMJIT_INLINE Error addUnreachableNode(Node* node) {
+    PodList<Node*>::Link* link = _baseZone.allocT<PodList<Node*>::Link>();
+    if (link == NULL)
+      return setError(kErrorNoHeapMemory);
+
+    link->setValue(node);
+    _unreachableList.append(link);
+
+    return kErrorOk;
+  }
+
   //! Remove unreachable code.
   virtual Error removeUnreachableCode();
 
+  // --------------------------------------------------------------------------
+  // [Code-Flow]
+  // --------------------------------------------------------------------------
+
+  //! Add returning node (i.e. node that returns and where liveness analysis
+  //! should start).
+  ASMJIT_INLINE Error addReturningNode(Node* node) {
+    PodList<Node*>::Link* link = _baseZone.allocT<PodList<Node*>::Link>();
+    if (link == NULL)
+      return setError(kErrorNoHeapMemory);
+
+    link->setValue(node);
+    _returningList.append(link);
+
+    return kErrorOk;
+  }
+
+  //! Add jump-flow data to the jcc flow list.
+  ASMJIT_INLINE Error addJccNode(Node* node) {
+    PodList<Node*>::Link* link = _baseZone.allocT<PodList<Node*>::Link>();
+    if (link == NULL)
+      return setError(kErrorNoHeapMemory);
+
+    link->setValue(node);
+    _jccList.append(link);
+
+    return kErrorOk;
+  }
+
   // --------------------------------------------------------------------------
   // [Analyze]
   // --------------------------------------------------------------------------
@@ -251,6 +292,8 @@ struct Context {
 
   //! Unreachable nodes.
   PodList<Node*> _unreachableList;
+  //! Returning nodes.
+  PodList<Node*> _returningList;
   //! Jump nodes.
   PodList<Node*> _jccList;
 

src/asmjit/build.h

@@ -277,7 +277,7 @@
 namespace asmjit { static inline int disabledTrace(...) { return 0; } }
 # if defined(ASMJIT_TRACE)
 #  define ASMJIT_TSEC(_Section_) _Section_
-#  define ASMJIT_TLOG ::printf(__VA_ARGS__)
+#  define ASMJIT_TLOG ::printf
 # else
 #  define ASMJIT_TSEC(_Section_) do {} while(0)
 #  define ASMJIT_TLOG 0 && ::asmjit::disabledTrace

src/asmjit/host.h

@@ -5,8 +5,8 @@
 // Zlib - See LICENSE.md file in the package.
 
 // [Guard]
-#ifndef _ASMJIT_ARCH_H
-#define _ASMJIT_ARCH_H
+#ifndef _ASMJIT_HOST_H
+#define _ASMJIT_HOST_H
 
 // [Dependencies - Core]
 #include "base.h"
@@ -56,4 +56,4 @@ typedef X86YmmVar YmmVar;
 #endif // ASMJIT_ARCH_X86 || ASMJIT_ARCH_X64
 
 // [Guard]
-#endif // _ASMJIT_ARCH_H
+#endif // _ASMJIT_HOST_H

src/asmjit/x86/x86compiler.cpp

@@ -793,14 +793,24 @@ static ASMJIT_INLINE size_t X86Compiler_getInstSize(uint32_t code) {
 static InstNode* X86Compiler_newInst(X86Compiler* self, void* p, uint32_t code, uint32_t options, Operand* opList, uint32_t opCount) {
   if (IntUtil::inInterval<uint32_t>(code, _kX86InstIdJbegin, _kX86InstIdJend)) {
     JumpNode* node = new(p) JumpNode(self, code, options, opList, opCount);
-    TargetNode* jTarget = self->getTargetById(opList[0].getId());
+    TargetNode* jTarget = NULL;
+
+    if ((options & kInstOptionUnfollow) == 0) {
+      if (opList[0].isLabel())
+        jTarget = self->getTargetById(opList[0].getId());
+      else
+        options |= kInstOptionUnfollow;
+    }
 
     node->orFlags(code == kX86InstIdJmp ? kNodeFlagIsJmp | kNodeFlagIsTaken : kNodeFlagIsJcc);
     node->_target = jTarget;
-    node->_jumpNext = static_cast<JumpNode*>(jTarget->_from);
+    node->_jumpNext = NULL;
 
-    jTarget->_from = node;
-    jTarget->addNumRefs();
+    if (jTarget) {
+      node->_jumpNext = static_cast<JumpNode*>(jTarget->_from);
+      jTarget->_from = node;
+      jTarget->addNumRefs();
+    }
 
     // The 'jmp' is always taken, conditional jump can contain hint, we detect it.
     if (code == kX86InstIdJmp)

src/asmjit/x86/x86compiler.h

@@ -2448,6 +2448,12 @@ struct ASMJIT_VCLASS X86Compiler : public Compiler {
 
   ASMJIT_X86_EMIT_OPTIONS(X86Compiler)
 
+  //! Force the compiler to not follow the conditional or unconditional jump.
+  ASMJIT_INLINE X86Compiler& unfollow() {
+    _instOptions |= kInstOptionUnfollow;
+    return *this;
+  }
+
   // --------------------------------------------------------------------------
   // [Members]
   // --------------------------------------------------------------------------

src/asmjit/x86/x86context.cpp

@@ -1895,35 +1895,6 @@ static void X86Context_prepareSingleVarInst(uint32_t instId, VarAttr* va) {
 // [asmjit::X86Context - Helpers]
 // ============================================================================
 
-//! \internal
-//!
-//! Add unreachable-flow data to the unreachable flow list.
-static ASMJIT_INLINE Error X86Context_addUnreachableNode(X86Context* self, Node* node) {
-  PodList<Node*>::Link* link = self->_baseZone.allocT<PodList<Node*>::Link>();
-  if (link == NULL)
-    return self->setError(kErrorNoHeapMemory);
-
-  link->setValue(node);
-  self->_unreachableList.append(link);
-
-  return kErrorOk;
-}
-
-//! \internal
-//!
-//! Add jump-flow data to the jcc flow list.
-static ASMJIT_INLINE Error X86Context_addJccNode(X86Context* self, Node* node) {
-  PodList<Node*>::Link* link = self->_baseZone.allocT<PodList<Node*>::Link>();
-
-  if (link == NULL)
-    ASMJIT_PROPAGATE_ERROR(self->setError(kErrorNoHeapMemory));
-
-  link->setValue(node);
-  self->_jccList.append(link);
-
-  return kErrorOk;
-}
-
 //! \internal
 //!
 //! Get mask of all registers actually used to pass function arguments.
@@ -2181,7 +2152,7 @@ Error X86Context::fetch() {
 
   // Function flags.
   func->clearFuncFlags(
-    kFuncFlagIsNaked |
+    kFuncFlagIsNaked    |
     kX86FuncFlagPushPop |
     kX86FuncFlagEmms    |
     kX86FuncFlagSFence  |
@@ -2660,8 +2631,6 @@ _NextGroup:
         // Handle conditional/unconditional jump.
         if (node->isJmpOrJcc()) {
           JumpNode* jNode = static_cast<JumpNode*>(node);
-
-          Node* jNext = jNode->getNext();
           TargetNode* jTarget = jNode->getTarget();
 
           // If this jump is unconditional we put next node to unreachable node
@@ -2671,13 +2640,23 @@ _NextGroup:
           // We also advance our node pointer to the target node to simulate
           // natural flow of the function.
           if (jNode->isJmp()) {
-            if (!jNext->isFetched())
-              ASMJIT_PROPAGATE_ERROR(X86Context_addUnreachableNode(this, jNext));
+            if (!next->isFetched())
+              ASMJIT_PROPAGATE_ERROR(addUnreachableNode(next));
+
+            // Jump not followed.
+            if (jTarget == NULL) {
+              ASMJIT_PROPAGATE_ERROR(addReturningNode(jNode));
+              goto _NextGroup;
+            }
 
             node_ = jTarget;
             goto _Do;
           }
           else {
+            // Jump not followed.
+            if (jTarget == NULL)
+              break;
+
             if (jTarget->isFetched()) {
               uint32_t jTargetFlowId = jTarget->getFlowId();
 
@@ -2688,13 +2667,12 @@ _NextGroup:
                 jNode->orFlags(kNodeFlagIsTaken);
               }
             }
-            else if (jNext->isFetched()) {
+            else if (next->isFetched()) {
               node_ = jTarget;
               goto _Do;
             }
             else {
-              ASMJIT_PROPAGATE_ERROR(X86Context_addJccNode(this, jNode));
-
+              ASMJIT_PROPAGATE_ERROR(addJccNode(jNode));
               node_ = X86Context_getJccFlow(jNode);
               goto _Do;
             }
@@ -2759,6 +2737,7 @@ _NextGroup:
       // ----------------------------------------------------------------------
 
       case kNodeTypeEnd: {
+        ASMJIT_PROPAGATE_ERROR(addReturningNode(node_));
         goto _NextGroup;
       }
 
@@ -2768,8 +2747,9 @@ _NextGroup:
 
       case kNodeTypeRet: {
         RetNode* node = static_cast<RetNode*>(node_);
-        X86FuncDecl* decl = func->getDecl();
+        ASMJIT_PROPAGATE_ERROR(addReturningNode(node));
 
+        X86FuncDecl* decl = func->getDecl();
         if (decl->hasRet()) {
           const FuncInOut& ret = decl->getRet(0);
           uint32_t retClass = x86VarTypeToClass(ret.getVarType());
@@ -2802,7 +2782,10 @@ _NextGroup:
           }
           VI_END(node_);
         }
-        break;
+
+        if (!next->isFetched())
+          ASMJIT_PROPAGATE_ERROR(addUnreachableNode(next));
+        goto _NextGroup;
       }
 
       // ----------------------------------------------------------------------
@@ -2946,6 +2929,14 @@ _NextGroup:
   } while (node_ != stop);
 
 _Done:
+  // Mark exit label and end node as fetched, otherwise they can be removed by
+  // `removeUnreachableCode()`, which would lead to crash in some later step.
+  node_ = func->getEnd();
+  if (!node_->isFetched()) {
+    func->getExitNode()->setFlowId(++flowId);
+    node_->setFlowId(++flowId);
+  }
+
   ASMJIT_TLOG("[Fetch] === Done ===\n\n");
   return kErrorOk;
 
@@ -3771,8 +3762,12 @@ ASMJIT_INLINE uint32_t X86VarAlloc::guessAlloc(VarData* vd, uint32_t allocableRe
       break;
 
     // Advance on non-conditional jump.
-    if (node->hasFlag(kNodeFlagIsJmp))
+    if (node->hasFlag(kNodeFlagIsJmp)) {
       node = static_cast<JumpNode*>(node)->getTarget();
+      // Stop on jump that is not followed.
+      if (node == NULL)
+        break;
+    }
 
     node = node->getNext();
     ASMJIT_ASSERT(node != NULL);
@@ -4378,8 +4373,12 @@ ASMJIT_INLINE uint32_t X86CallAlloc::guessAlloc(VarData* vd, uint32_t allocableR
       break;
 
     // Advance on non-conditional jump.
-    if (node->hasFlag(kNodeFlagIsJmp))
+    if (node->hasFlag(kNodeFlagIsJmp)) {
       node = static_cast<JumpNode*>(node)->getTarget();
+      // Stop on jump that is not followed.
+      if (node == NULL)
+        break;
+    }
 
     node = node->getNext();
     ASMJIT_ASSERT(node != NULL);
@@ -5317,6 +5316,14 @@ _NextGroup:
           JumpNode* node = static_cast<JumpNode*>(node_);
           TargetNode* jTarget = node->getTarget();
 
+          // Target not followed.
+          if (jTarget == NULL) {
+            if (node->isJmp())
+              goto _NextGroup;
+            else
+              break;
+          }
+
           if (node->isJmp()) {
             if (jTarget->hasState()) {
               compiler->_setCursor(node->getPrev());
@@ -5526,7 +5533,10 @@ _NextGroup:
     // If node is `jmp` we follow it as well.
     if (node_->isJmp()) {
       node_ = static_cast<JumpNode*>(node_)->getTarget();
-      goto _Advance;
+      if (node_ == NULL)
+        goto _NextGroup;
+      else
+        goto _Advance;
     }
 
     // Handle stop nodes.

src/asmjit/x86/x86inst.h

@@ -1164,12 +1164,6 @@ ASMJIT_ENUM(X86InstId) {
 
 //! X86/X64 instruction emit options, mainly for internal purposes.
 ASMJIT_ENUM(X86InstOptions) {
-  //! Emit instruction with LOCK prefix.
-  //!
-  //! If this option is used and instruction doesn't support LOCK prefix an
-  //! invalid instruction error is generated.
-  kX86InstOptionLock = 0x00000010,
-
   //! Force REX prefix (X64).
   //!
   //! This option should be used carefully as there are combinations of
@@ -1183,11 +1177,17 @@ ASMJIT_ENUM(X86InstOptions) {
   //! Reserved by `X86Assembler`, do not use!
   _kX86InstOptionNoRex = 0x00000080,
 
+  //! Emit instruction with LOCK prefix.
+  //!
+  //! If this option is used and instruction doesn't support LOCK prefix an
+  //! invalid instruction error is generated.
+  kX86InstOptionLock = 0x00000100,
+
   //! Force 3-byte VEX prefix even if the instruction is encodable by 2-byte
   //! VEX prefix (AVX).
   //!
   //! Ignored if the instruction is not AVX or `kX86InstOptionEVEX` is used.
-  kX86InstOptionVex3 = 0x00000100,
+  kX86InstOptionVex3 = 0x00001000,
 
   //! Force 4-byte EVEX prefix even if the instruction is encodable by using
   //! VEX prefix. Please note that all higher bits from `kX86InstOptionEvex`

src/asmjit/x86/x86operand.h

@@ -282,7 +282,7 @@ struct X86ZmmReg { Operand::VRegOp data; };
 //! 16 Xmm/Ymm/Zmm registers. AVX512 instruction set doubles the number of SIMD
 //! registers (Xmm/Ymm/Zmm) to 32, this mode has to be explicitly enabled to
 //! take effect as it changes some assumptions.
-//! 
+//!
 //! `X86RegCount` is also used extensively by `X86Compiler`'s register allocator
 //! and data structures. Fp registers were omitted as they are never mapped to
 //! variables, thus, not needed to be managed.