Various improvements related to legalization code.

1) In makeHelperCall(), function pointers that are created should have type IceType_i32, not the functions' own return type. 2) In legalize(), change the name of WillHaveRegister to MustHaveRegister. Add a comment to clarify the condition being computed. 3) In legalize(), add an assert to make sure that vector "constants" don't get legalized (other than undef). There should be no constants of vector type. 4) In copyToReg(), replace an unnecessary use of Src->getType(). BUG=none R=stichnot@chromium.org Review URL: https://codereview.chromium.org/385133006

Various improvements related to legalization code.
ad8f7265 · Matt Wala · 0ecabc82 · ad8f7265 · ad8f7265
Commit ad8f7265 authored Jul 14, 2014 by Matt Wala
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Showing with 12 additions and 6 deletions

IceTargetLoweringX8632.cpp src/IceTargetLoweringX8632.cpp +9 -4

IceTargetLoweringX8632.h src/IceTargetLoweringX8632.h +3 -2

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--- a/src/IceTargetLoweringX8632.cpp
+++ b/src/IceTargetLoweringX8632.cpp
@@ -2756,7 +2756,7 @@ void TargetX8632::lowerUnreachable(const InstUnreachable * /*Inst*/) {
 Variable *TargetX8632::copyToReg(Operand *Src, int32_t RegNum) {
  Type Ty = Src->getType();
  Variable *Reg = makeReg(Ty, RegNum);
-  if (isVectorType(Src->getType())) {
+  if (isVectorType(Ty)) {
    _movp(Reg, Src);
  } else {
    _mov(Reg, Src);
@@ -2827,6 +2827,8 @@ Operand *TargetX8632::legalize(Operand *From, LegalMask Allowed,
        From = Ctx->getConstantZero(From->getType());
      }
    }
+    // There should be no constants of vector type (other than undef).
+    assert(!isVectorType(From->getType()));
    bool NeedsReg = false;
    if (!(Allowed & Legal_Imm))
      // Immediate specifically not allowed
@@ -2846,13 +2848,16 @@ Operand *TargetX8632::legalize(Operand *From, LegalMask Allowed,
    return From;
  }
  if (Variable *Var = llvm::dyn_cast<Variable>(From)) {
+    // Check if the variable is guaranteed a physical register.  This
+    // can happen either when the variable is pre-colored or when it is
+    // assigned infinite weight.
+    bool MustHaveRegister =
+        (Var->hasReg() || Var->getWeight() == RegWeight::Inf);
    // We need a new physical register for the operand if:
    //   Mem is not allowed and Var isn't guaranteed a physical
    //   register, or
    //   RegNum is required and Var->getRegNum() doesn't match.
-    bool WillHaveRegister =
+    if ((!(Allowed & Legal_Mem) && !MustHaveRegister) ||
-        (Var->hasReg() || Var->getWeight() == RegWeight::Inf);
-    if ((!(Allowed & Legal_Mem) && !WillHaveRegister) ||
        (RegNum != Variable::NoRegister && RegNum != Var->getRegNum())) {
      Variable *Reg = copyToReg(From, RegNum);
      if (RegNum == Variable::NoRegister) {

--- a/src/IceTargetLoweringX8632.h
+++ b/src/IceTargetLoweringX8632.h
@@ -136,8 +136,9 @@ protected:
  InstCall *makeHelperCall(const IceString &Name, Variable *Dest,
                           SizeT MaxSrcs) {
    bool SuppressMangling = true;
-    Type Ty = Dest ? Dest->getType() : IceType_void;
+    const Type FunctionPointerType = IceType_i32;
-    Constant *CallTarget = Ctx->getConstantSym(Ty, 0, Name, SuppressMangling);
+    Constant *CallTarget =
+        Ctx->getConstantSym(FunctionPointerType, 0, Name, SuppressMangling);
    InstCall *Call = InstCall::create(Func, MaxSrcs, Dest, CallTarget);
    return Call;
  }