[cfe-commits] r126592 - in /cfe/trunk/lib/CodeGen: CGExpr.cpp CGExprScalar.cpp CGStmt.cpp CodeGenFunction.cpp CodeGenFunction.h
Chris Lattner
sabre at nondot.org
Sun Feb 27 15:02:32 PST 2011
Author: lattner
Date: Sun Feb 27 17:02:32 2011
New Revision: 126592
URL: http://llvm.org/viewvc/llvm-project?rev=126592&view=rev
Log:
Change the interface to ConstantFoldsToSimpleInteger to not encode
a bool + success into one tri-state integer, simplifying things.
Modified:
cfe/trunk/lib/CodeGen/CGExpr.cpp
cfe/trunk/lib/CodeGen/CGExprScalar.cpp
cfe/trunk/lib/CodeGen/CGStmt.cpp
cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
cfe/trunk/lib/CodeGen/CodeGenFunction.h
Modified: cfe/trunk/lib/CodeGen/CGExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExpr.cpp?rev=126592&r1=126591&r2=126592&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExpr.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExpr.cpp Sun Feb 27 17:02:32 2011
@@ -1715,10 +1715,10 @@
}
const Expr *condExpr = expr->getCond();
-
- if (int condValue = ConstantFoldsToSimpleInteger(condExpr)) {
+ bool CondExprBool;
+ if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
- if (condValue == -1) std::swap(live, dead);
+ if (!CondExprBool) std::swap(live, dead);
if (!ContainsLabel(dead))
return EmitLValue(live);
Modified: cfe/trunk/lib/CodeGen/CGExprScalar.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprScalar.cpp?rev=126592&r1=126591&r2=126592&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprScalar.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprScalar.cpp Sun Feb 27 17:02:32 2011
@@ -2257,8 +2257,9 @@
// If we have 0 && RHS, see if we can elide RHS, if so, just return 0.
// If we have 1 && X, just emit X without inserting the control flow.
- if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) {
- if (Cond == 1) { // If we have 1 && X, just emit X.
+ bool LHSCondVal;
+ if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) {
+ if (LHSCondVal) { // If we have 1 && X, just emit X.
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
// ZExt result to int or bool.
return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "land.ext");
@@ -2309,8 +2310,9 @@
// If we have 1 || RHS, see if we can elide RHS, if so, just return 1.
// If we have 0 || X, just emit X without inserting the control flow.
- if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) {
- if (Cond == -1) { // If we have 0 || X, just emit X.
+ bool LHSCondVal;
+ if (CGF.ConstantFoldsToSimpleInteger(E->getLHS(), LHSCondVal)) {
+ if (!LHSCondVal) { // If we have 0 || X, just emit X.
Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS());
// ZExt result to int or bool.
return Builder.CreateZExtOrBitCast(RHSCond, ResTy, "lor.ext");
@@ -2409,9 +2411,10 @@
// If the condition constant folds and can be elided, try to avoid emitting
// the condition and the dead arm.
- if (int Cond = CGF.ConstantFoldsToSimpleInteger(condExpr)){
+ bool CondExprBool;
+ if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
Expr *live = lhsExpr, *dead = rhsExpr;
- if (Cond == -1) std::swap(live, dead);
+ if (!CondExprBool) std::swap(live, dead);
// If the dead side doesn't have labels we need, and if the Live side isn't
// the gnu missing ?: extension (which we could handle, but don't bother
Modified: cfe/trunk/lib/CodeGen/CGStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGStmt.cpp?rev=126592&r1=126591&r2=126592&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGStmt.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGStmt.cpp Sun Feb 27 17:02:32 2011
@@ -359,10 +359,12 @@
// If the condition constant folds and can be elided, try to avoid emitting
// the condition and the dead arm of the if/else.
- if (int Cond = ConstantFoldsToSimpleInteger(S.getCond())) {
+ bool CondConstant;
+ if (ConstantFoldsToSimpleInteger(S.getCond(), CondConstant)) {
// Figure out which block (then or else) is executed.
- const Stmt *Executed = S.getThen(), *Skipped = S.getElse();
- if (Cond == -1) // Condition false?
+ const Stmt *Executed = S.getThen();
+ const Stmt *Skipped = S.getElse();
+ if (!CondConstant) // Condition false?
std::swap(Executed, Skipped);
// If the skipped block has no labels in it, just emit the executed block.
Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.cpp?rev=126592&r1=126591&r2=126592&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.cpp Sun Feb 27 17:02:32 2011
@@ -408,22 +408,23 @@
}
-/// ConstantFoldsToSimpleInteger - If the sepcified expression does not fold to
-/// a constant, or if it does but contains a label, return 0. If it constant
-/// folds to 'true' and does not contain a label, return 1, if it constant folds
-/// to 'false' and does not contain a label, return -1.
-int CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond) {
+/// ConstantFoldsToSimpleInteger - If the specified expression does not fold
+/// to a constant, or if it does but contains a label, return false. If it
+/// constant folds return true and set the boolean result in Result.
+bool CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond,
+ bool &ResultBool) {
// FIXME: Rename and handle conversion of other evaluatable things
// to bool.
Expr::EvalResult Result;
if (!Cond->Evaluate(Result, getContext()) || !Result.Val.isInt() ||
Result.HasSideEffects)
- return 0; // Not foldable, not integer or not fully evaluatable.
+ return false; // Not foldable, not integer or not fully evaluatable.
if (CodeGenFunction::ContainsLabel(Cond))
- return 0; // Contains a label.
+ return false; // Contains a label.
- return Result.Val.getInt().getBoolValue() ? 1 : -1;
+ ResultBool = Result.Val.getInt().getBoolValue();
+ return true;
}
@@ -442,14 +443,17 @@
if (CondBOp->getOpcode() == BO_LAnd) {
// If we have "1 && X", simplify the code. "0 && X" would have constant
// folded if the case was simple enough.
- if (ConstantFoldsToSimpleInteger(CondBOp->getLHS()) == 1) {
+ bool ConstantBool;
+ if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
+ ConstantBool) {
// br(1 && X) -> br(X).
return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
}
// If we have "X && 1", simplify the code to use an uncond branch.
// "X && 0" would have been constant folded to 0.
- if (ConstantFoldsToSimpleInteger(CondBOp->getRHS()) == 1) {
+ if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
+ ConstantBool) {
// br(X && 1) -> br(X).
return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock);
}
@@ -468,17 +472,22 @@
eval.end(*this);
return;
- } else if (CondBOp->getOpcode() == BO_LOr) {
+ }
+
+ if (CondBOp->getOpcode() == BO_LOr) {
// If we have "0 || X", simplify the code. "1 || X" would have constant
// folded if the case was simple enough.
- if (ConstantFoldsToSimpleInteger(CondBOp->getLHS()) == -1) {
+ bool ConstantBool;
+ if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
+ !ConstantBool) {
// br(0 || X) -> br(X).
return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
}
// If we have "X || 0", simplify the code to use an uncond branch.
// "X || 1" would have been constant folded to 1.
- if (ConstantFoldsToSimpleInteger(CondBOp->getRHS()) == -1) {
+ if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
+ !ConstantBool) {
// br(X || 0) -> br(X).
return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock);
}
Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.h?rev=126592&r1=126591&r2=126592&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.h Sun Feb 27 17:02:32 2011
@@ -2045,10 +2045,9 @@
static bool ContainsLabel(const Stmt *S, bool IgnoreCaseStmts = false);
/// ConstantFoldsToSimpleInteger - If the specified expression does not fold
- /// to a constant, or if it does but contains a label, return 0. If it
- /// constant folds to 'true' and does not contain a label, return 1, if it
- /// constant folds to 'false' and does not contain a label, return -1.
- int ConstantFoldsToSimpleInteger(const Expr *Cond);
+ /// to a constant, or if it does but contains a label, return false. If it
+ /// constant folds return true and set the boolean result in Result.
+ bool ConstantFoldsToSimpleInteger(const Expr *Cond, bool &Result);
/// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an
/// if statement) to the specified blocks. Based on the condition, this might
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