[clang] 710749f - [clang][Interp] Optionally cast comparison result to non-bool
Timm Bäder via cfe-commits
cfe-commits at lists.llvm.org
Thu Jun 1 01:36:49 PDT 2023
Author: Timm Bäder
Date: 2023-06-01T10:36:33+02:00
New Revision: 710749f78695b0e00026e5ff7c9f94e08e7b482a
URL: https://github.com/llvm/llvm-project/commit/710749f78695b0e00026e5ff7c9f94e08e7b482a
DIFF: https://github.com/llvm/llvm-project/commit/710749f78695b0e00026e5ff7c9f94e08e7b482a.diff
LOG: [clang][Interp] Optionally cast comparison result to non-bool
Our comparison opcodes always produce a Boolean value and push it on the
stack. However, the result of such a comparison in C is int, so the
later code expects an integer value on the stack.
Work around this problem by casting the boolean value to int in those
cases. This is not ideal for C however. The comparison is usually
wrapped in a IntegerToBool cast anyway.
Differential Revision: https://reviews.llvm.org/D149645
Added:
clang/test/AST/Interp/c.c
Modified:
clang/lib/AST/Interp/ByteCodeExprGen.cpp
Removed:
################################################################################
diff --git a/clang/lib/AST/Interp/ByteCodeExprGen.cpp b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
index df7c4a72f21a7..1be131be66e3b 100644
--- a/clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -237,19 +237,31 @@ bool ByteCodeExprGen<Emitter>::VisitBinaryOperator(const BinaryOperator *BO) {
if (!visit(LHS) || !visit(RHS))
return false;
+ // For languages such as C, cast the result of one
+ // of our comparision opcodes to T (which is usually int).
+ auto MaybeCastToBool = [this, T, BO](bool Result) {
+ if (!Result)
+ return false;
+ if (DiscardResult)
+ return this->emitPop(*T, BO);
+ if (T != PT_Bool)
+ return this->emitCast(PT_Bool, *T, BO);
+ return true;
+ };
+
switch (BO->getOpcode()) {
case BO_EQ:
- return Discard(this->emitEQ(*LT, BO));
+ return MaybeCastToBool(this->emitEQ(*LT, BO));
case BO_NE:
- return Discard(this->emitNE(*LT, BO));
+ return MaybeCastToBool(this->emitNE(*LT, BO));
case BO_LT:
- return Discard(this->emitLT(*LT, BO));
+ return MaybeCastToBool(this->emitLT(*LT, BO));
case BO_LE:
- return Discard(this->emitLE(*LT, BO));
+ return MaybeCastToBool(this->emitLE(*LT, BO));
case BO_GT:
- return Discard(this->emitGT(*LT, BO));
+ return MaybeCastToBool(this->emitGT(*LT, BO));
case BO_GE:
- return Discard(this->emitGE(*LT, BO));
+ return MaybeCastToBool(this->emitGE(*LT, BO));
case BO_Sub:
if (BO->getType()->isFloatingType())
return Discard(this->emitSubf(getRoundingMode(BO), BO));
@@ -925,6 +937,15 @@ bool ByteCodeExprGen<Emitter>::visitConditional(
if (!this->visit(Condition))
return false;
+
+ // C special case: Convert to bool because our jump ops need that.
+ // TODO: We probably want this to be done in visitBool().
+ if (std::optional<PrimType> CondT = classify(Condition->getType());
+ CondT && CondT != PT_Bool) {
+ if (!this->emitCast(*CondT, PT_Bool, E))
+ return false;
+ }
+
if (!this->jumpFalse(LabelFalse))
return false;
diff --git a/clang/test/AST/Interp/c.c b/clang/test/AST/Interp/c.c
new file mode 100644
index 0000000000000..fe794bb014e7c
--- /dev/null
+++ b/clang/test/AST/Interp/c.c
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -verify %s
+// RUN: %clang_cc1 -verify=ref %s
+
+/// expected-no-diagnostics
+/// ref-no-diagnostics
+
+_Static_assert(1, "");
+_Static_assert(0 != 1, "");
+_Static_assert(1.0 == 1.0, "");
+_Static_assert( (5 > 4) + (3 > 2) == 2, "");
+
+int a = (1 == 1 ? 5 : 3);
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