[clang] [NFC] Add assertion to ensure FiniteMathOnly is in sync with HonorINFs and HonorNANs. (PR #97342)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-driver

Author: Zahira Ammarguellat (zahiraam)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/97342.diff


6 Files Affected:

- (modified) clang/include/clang/Basic/LangOptions.h (+5) 
- (modified) clang/lib/Driver/ToolChains/Clang.cpp (+11-1) 
- (modified) clang/lib/Frontend/InitPreprocessor.cpp (+1-1) 
- (modified) clang/test/CodeGen/fp-floatcontrol-stack.cpp (+1-1) 
- (modified) clang/test/Sema/warn-infinity-nan-disabled-lnx.cpp (+5-4) 
- (modified) clang/test/Sema/warn-infinity-nan-disabled-win.cpp (+4-4) 


``````````diff
diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
index 91f1c2f2e6239..e1adcb3a95f18 100644
--- a/clang/include/clang/Basic/LangOptions.h
+++ b/clang/include/clang/Basic/LangOptions.h
@@ -816,6 +816,11 @@ class FPOptions {
     setAllowFPReassociate(LO.AllowFPReassoc);
     setNoHonorNaNs(LO.NoHonorNaNs);
     setNoHonorInfs(LO.NoHonorInfs);
+    // Ensure that if FiniteMathOnly is enabled, NoHonorNaNs and NoHonorInfs are
+    // also enabled. This is because FiniteMathOnly mode assumes no NaNs or Infs
+    // are present in computations.
+    assert((LO.FiniteMathOnly == (LO.NoHonorInfs && LO.NoHonorNaNs)) &&
+           "inf/nan inconsistent internal state");
     setNoSignedZero(LO.NoSignedZero);
     setAllowReciprocal(LO.AllowRecip);
     setAllowApproxFunc(LO.ApproxFunc);
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index aa285c39f14b4..65257e3c4c9d9 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -3295,7 +3295,17 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
   }
 
   // Handle __FINITE_MATH_ONLY__ similarly.
-  if (!HonorINFs && !HonorNaNs)
+  bool InfValues, NanValues = true;
+  auto processArg = [&](const auto *Arg) {
+    if (StringRef(Arg->getValue()) == "-menable-no-nans")
+      NanValues = false;
+    if (StringRef(Arg->getValue()) == "-menable-no-infs")
+      InfValues = false;
+  };
+  for (auto *Arg : Args.filtered(options::OPT_Xclang)) {
+    processArg(Arg);
+  }
+  if ((!HonorINFs && !HonorNaNs) || (!NanValues && !InfValues))
     CmdArgs.push_back("-ffinite-math-only");
 
   if (const Arg *A = Args.getLastArg(options::OPT_mfpmath_EQ)) {
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index 5e52555c6fee9..e7e02e9ddf96e 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -1311,7 +1311,7 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
   if (!LangOpts.MathErrno)
     Builder.defineMacro("__NO_MATH_ERRNO__");
 
-  if (LangOpts.FastMath || LangOpts.FiniteMathOnly)
+  if (LangOpts.FastMath || (LangOpts.NoHonorInfs && LangOpts.NoHonorNaNs))
     Builder.defineMacro("__FINITE_MATH_ONLY__", "1");
   else
     Builder.defineMacro("__FINITE_MATH_ONLY__", "0");
diff --git a/clang/test/CodeGen/fp-floatcontrol-stack.cpp b/clang/test/CodeGen/fp-floatcontrol-stack.cpp
index 090da25d21207..237c9d4f9a37e 100644
--- a/clang/test/CodeGen/fp-floatcontrol-stack.cpp
+++ b/clang/test/CodeGen/fp-floatcontrol-stack.cpp
@@ -1,7 +1,7 @@
 // RUN: %clang_cc1 -triple x86_64-linux-gnu -ffp-contract=on -DDEFAULT=1 -emit-llvm -o - %s | FileCheck --check-prefix=CHECK-DDEFAULT %s
 // RUN: %clang_cc1 -triple x86_64-linux-gnu -ffp-contract=on -DEBSTRICT=1 -ffp-exception-behavior=strict -emit-llvm -o - %s | FileCheck --check-prefix=CHECK-DEBSTRICT %s
 // RUN: %clang_cc1 -triple x86_64-linux-gnu -DFAST=1 -ffast-math -ffp-contract=fast -emit-llvm -o - %s | FileCheck --check-prefix=CHECK-FAST %s
-// RUN: %clang_cc1 -triple x86_64-linux-gnu -ffp-contract=on -DNOHONOR=1 -menable-no-infs -menable-no-nans -emit-llvm -o - %s | FileCheck --check-prefix=CHECK-NOHONOR %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -ffp-contract=on -DNOHONOR=1 -ffinite-math-only -menable-no-infs -menable-no-nans -emit-llvm -o - %s | FileCheck --check-prefix=CHECK-NOHONOR %s
 
 #define FUN(n) \
   (float z) { return n * z + n; }
diff --git a/clang/test/Sema/warn-infinity-nan-disabled-lnx.cpp b/clang/test/Sema/warn-infinity-nan-disabled-lnx.cpp
index 03a432e05851d..cb719c3a519da 100644
--- a/clang/test/Sema/warn-infinity-nan-disabled-lnx.cpp
+++ b/clang/test/Sema/warn-infinity-nan-disabled-lnx.cpp
@@ -1,10 +1,11 @@
 // RUN: %clang_cc1 -x c++ -verify=no-inf-no-nan \
-// RUN: -triple powerpc64le-unknown-unknown %s -menable-no-infs \
-// RUN: -menable-no-nans -std=c++23
+// RUN: -triple powerpc64le-unknown-unknown %s \
+// RUN: -ffinite-math-only -std=c++23
 
 // RUN: %clang_cc1 -x c++ -verify=no-inf-no-nan \
-// RUN: -triple powerpc64le-unknown-unknown %s -menable-no-infs \
-// RUN: -menable-no-nans -funsafe-math-optimizations -std=c++23
+// RUN: -triple powerpc64le-unknown-unknown %s \
+// RUN: -ffinite-math-only -funsafe-math-optimizations \
+// RUN: -std=c++23
 
 // RUN: %clang_cc1 -x c++ -verify=no-fast -triple powerpc64le-unknown-unknown \
 // RUN: %s -std=c++23
diff --git a/clang/test/Sema/warn-infinity-nan-disabled-win.cpp b/clang/test/Sema/warn-infinity-nan-disabled-win.cpp
index 51f9d325619ba..4bf3355926634 100644
--- a/clang/test/Sema/warn-infinity-nan-disabled-win.cpp
+++ b/clang/test/Sema/warn-infinity-nan-disabled-win.cpp
@@ -2,12 +2,12 @@
 // on Windows the NAN macro is defined using INFINITY. See below.
 
 // RUN: %clang_cc1 -x c++ -verify=no-inf-no-nan \
-// RUN: -triple powerpc64le-unknown-unknown %s -menable-no-infs \
-// RUN: -menable-no-nans -std=c++23
+// RUN: -triple powerpc64le-unknown-unknown %s -ffinite-math-only -std=c++23
 
 // RUN: %clang_cc1 -x c++ -verify=no-inf-no-nan \
-// RUN: -triple powerpc64le-unknown-unknown %s -menable-no-infs \
-// RUN: -menable-no-nans -funsafe-math-optimizations -std=c++23
+// RUN: -triple powerpc64le-unknown-unknown %s \
+// RUN: -ffinite-math-only -funsafe-math-optimizations \
+// RUN: -std=c++23
 
 // RUN: %clang_cc1 -x c++ -verify=no-fast -triple powerpc64le-unknown-unknown \
 // RUN: %s -std=c++23

``````````

</details>


https://github.com/llvm/llvm-project/pull/97342