[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-05-26 Thread via cfe-commits 

s-watanabe314 wrote:

Thank you for confirming.

@MaskRay, do you have any comments regarding the handling of warning messages?

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-05-15 Thread Andy Kaylor via cfe-commits 

andykaylor wrote:

@s-watanabe314 I apologize for the very long delay in responding. This fell off 
my radar for a while.

I think your latest proposed handling of warnings looks good, but I'd like to 
see input from @MaskRay also.

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-04-14 Thread via cfe-commits 

s-watanabe314 wrote:

@andykaylor I would appreciate your comments on this.

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-04-05 Thread via cfe-commits 


@@ -2997,6 +2997,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   LangOptions::ComplexRangeKind Range = LangOptions::ComplexRangeKind::CX_None;
   std::string ComplexRangeStr = "";
   std::string GccRangeComplexOption = "";
+  std::string LastComplexRangeOption = "";

s-watanabe314 wrote:

Does this mean that `= ""` is unnecessary? I initialized it in the same way as 
`GccRangeComplexOption`, but should I remove it?

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-04-04 Thread Fangrui Song via cfe-commits 

https://github.com/MaskRay edited 
https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-04-03 Thread via cfe-commits 

s-watanabe314 wrote:

> I would like to see warnings for -fno-fast-math overriding explicit complex 
> range options, especially since GCC doesn't do that.


Is "explicit complex range options" referring to the `-fcomplex-arithmetic=` 
and GCC options? If so, when `-fno-fast-math` overrides other options, should I 
modify the behavior as follows?

- Issue a warning when `-fno-fast-math` overrides explicit options.

|Option|Warning|
|-|-|
|-fcx-limited-range -fno-fast-math|warning: overriding '-fcx-limited-range' 
option with '-fno-fast-math'|
|-fcx-fortran-rules -fno-fast-math|warning: overriding '-fcx-fortran-rules' 
option with '-fno-fast-math'|
|-fcomplex-arithmetic=basic -fno-fast-math|warning: overriding 
'-fcomplex-arithmetic=basic' option with '-fno-fast-math'|

- Do not issue a warning when overriding non-explicit options.

|Option|Warning|
|-|-|
|-ffast-math -fno-fast-math|No warning|
|-ffp-model=aggressive -fno-fast-math|No warning|


Furthermore, if `-fno-fast-math` means that it resets the state to the default, 
is a warning always unnecessary if another option is specified after 
`-fno-fast-math`? To implement this, I think we can assign `CX_None` to `Range` 
instead of `CX_Full` when the `-fno-fast-math` is specified.

- All of the following examples do not issue a warning:

|Option|Warning|
|-|-|
|-fno-fast-math -fcx-limited-range|No warning|
|-fno-fast-math -fcx-fortran-rules|No warning|
|-fno-fast-math -fcomplex-arithmetic=basic|No warning|
|-fno-fast-math -ffp-model=aggressive|No warning|

> This may contradict things I've said earlier, but it doesn't seem like we 
> should treat the GCC options differently than the clang-specific options with 
> regard to whether or not we issue warnings. Also, the warnings are 
> referencing options that the user didn't explicitly specify.


I agree that we shouldn't treat them differently. `GccRangeComplexOption` is 
only used to determine whether to issue a warning. I'm considering replacing it 
with `LastComplexRangeOption`. This would allow the warning message to directly 
reference the user-specified option.

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-04-02 Thread Fangrui Song via cfe-commits 


@@ -3148,6 +3158,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
  ComplexArithmeticStr(RangeVal));
 }
   }
+  LastComplexRangeOption = "-fcomplex-arithmetic";

MaskRay wrote:

`Arg::getSpelling` returns the spelling. Don't write the string literal 
separately.

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-04-02 Thread Fangrui Song via cfe-commits 


@@ -2997,6 +2997,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   LangOptions::ComplexRangeKind Range = LangOptions::ComplexRangeKind::CX_None;
   std::string ComplexRangeStr = "";
   std::string GccRangeComplexOption = "";
+  std::string LastComplexRangeOption = "";

MaskRay wrote:

`std::string LastComplexRangeOption` default initialization

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-04-01 Thread Fangrui Song via cfe-commits 


@@ -177,14 +177,83 @@
 // RUN: %clang -### -target x86_64 -ffast-math -fcomplex-arithmetic=basic -c 
%s 2>&1 \
 // RUN:   | FileCheck --check-prefix=BASIC %s
 
-// BASIC: -complex-range=basic
-// FULL: -complex-range=full
-// PRMTD: -complex-range=promoted
-// BASIC-NOT: -complex-range=improved
-// CHECK-NOT: -complex-range=basic
-// IMPRVD: -complex-range=improved
-// IMPRVD-NOT: -complex-range=basic
-// CHECK-NOT: -complex-range=improved
+// RUN: %clang -### -target x86_64 -fcx-limited-range -fno-fast-math \

MaskRay wrote:

`-target ` has been deprecated for a long time. `--target=` for new tests

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-03-26 Thread via cfe-commits 


@@ -177,14 +177,45 @@
 // RUN: %clang -### -target x86_64 -ffast-math -fcomplex-arithmetic=basic -c 
%s 2>&1 \
 // RUN:   | FileCheck --check-prefix=BASIC %s
 
-// BASIC: -complex-range=basic
-// FULL: -complex-range=full
-// PRMTD: -complex-range=promoted
-// BASIC-NOT: -complex-range=improved
-// CHECK-NOT: -complex-range=basic
-// IMPRVD: -complex-range=improved
-// IMPRVD-NOT: -complex-range=basic
-// CHECK-NOT: -complex-range=improved
+// RUN: %clang -### -target x86_64 -fcx-limited-range -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN21 %s
+
+// RUN: %clang -### -Werror -target x86_64 -fno-cx-limited-range 
-fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL %s
+
+// RUN: %clang -### -target x86_64 -fcx-fortran-rules -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN22 %s
+
+// RUN: %clang -### -Werror -target x86_64 -fno-cx-fortran-rules 
-fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL %s
+
+// RUN: %clang -### -Werror -target x86_64 -ffast-math -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL %s
+
+// RUN: %clang -### -target x86_64 -fcomplex-arithmetic=basic -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN23 %s
+
+// RUN: %clang -### -target x86_64 -fcomplex-arithmetic=promoted 
-fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN24 %s
+
+// RUN: %clang -### -target x86_64 -fcomplex-arithmetic=improved 
-fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN25 %s
+
+// RUN: %clang -### -Werror -target x86_64 -fcomplex-arithmetic=full 
-fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL %s
+
+// RUN: %clang -### -target x86_64 -ffp-model=aggressive -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN23 %s
+
+// RUN: %clang -### -target x86_64 -ffp-model=fast -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN24 %s
+
+// RUN: %clang -### -Werror -target x86_64 -ffp-model=precise -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL %s
+
+// RUN: %clang -### -Werror -target x86_64 -ffp-model=strict -fno-fast-math \

s-watanabe314 wrote:

I added test cases.

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-03-26 Thread via cfe-commits 


@@ -2997,6 +2997,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   LangOptions::ComplexRangeKind Range = LangOptions::ComplexRangeKind::CX_None;
   std::string ComplexRangeStr = "";
   std::string GccRangeComplexOption = "";
+  std::string LastComplexRangeOption = "";

s-watanabe314 wrote:

Thank you for your feedback!
>  If you just set GccRangeComplexOption to empty for -ffast-math and 
> -fno-fast-math, would that give us reasonable diagnostics?

I think it's difficult. I believe diagnostics should be emitted when `Range` 
specified with options other than `-ffast-math` is overridden by 
`-fno-fast-math`. To distinguish between these cases, I think we need a 
variable that determines what options, including Clang-specific options, were 
specified before `-fno-fast-math`. Even if we empty `GccRangeComplexOption` 
when `-ffast-math` is spcified, it's impossible to distinguish whether the 
preceding option before `-fno-fast-math` was `-ffast-math` or 
`-fcomplex-arithmetic=basic`. If it's acceptable to assign "-ffp-model" or 
"-fcomplex-arithmetic" to `GccRangeComplexOption`, then a new variable might 
not be necessary.

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-03-26 Thread via cfe-commits 

https://github.com/s-watanabe314 updated 
https://github.com/llvm/llvm-project/pull/132680

>From 9265cb96cc3129fada722d7195a1cf04e985ba33 Mon Sep 17 00:00:00 2001
From: s-watanabe314 
Date: Fri, 14 Mar 2025 11:56:32 +0900
Subject: [PATCH 1/2] [Clang][Driver] Override complex number calculation
 method by -fno-fast-math

This patch fixes a bug where -fno-fast-math doesn't revert the complex
number calculation method to the default. The priority of overriding
options related to complex number calculations differs slightly from
GCC, as discussed in:

https://discourse.llvm.org/t/the-priority-of-fno-fast-math-regarding-complex-number-calculations/84679
---
 clang/lib/Driver/ToolChains/Clang.cpp | 22 +-
 clang/test/Driver/range.c | 61 +++
 2 files changed, 74 insertions(+), 9 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp 
b/clang/lib/Driver/ToolChains/Clang.cpp
index fb3ed2db0e3c0..484ced9885883 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -2997,6 +2997,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   LangOptions::ComplexRangeKind Range = LangOptions::ComplexRangeKind::CX_None;
   std::string ComplexRangeStr = "";
   std::string GccRangeComplexOption = "";
+  std::string LastComplexRangeOption = "";
 
   auto setComplexRange = [&](LangOptions::ComplexRangeKind NewRange) {
 // Warn if user expects to perform full implementation of complex
@@ -3015,7 +3016,12 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
 if (Aggressive) {
   HonorINFs = false;
   HonorNaNs = false;
-  setComplexRange(LangOptions::ComplexRangeKind::CX_Basic);
+  // If the last specified option related to complex range is
+  // -fno-fast-math, override 'Range' without warning.
+  if (LastComplexRangeOption == "-fno-fast-math")
+Range = LangOptions::ComplexRangeKind::CX_Basic;
+  else
+setComplexRange(LangOptions::ComplexRangeKind::CX_Basic);
 } else {
   HonorINFs = true;
   HonorNaNs = true;
@@ -3080,6 +3086,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   EmitComplexRangeDiag(D, GccRangeComplexOption, "-fcx-limited-range");
   }
   GccRangeComplexOption = "-fcx-limited-range";
+  LastComplexRangeOption = "-fcx-limited-range";
   Range = LangOptions::ComplexRangeKind::CX_Basic;
   break;
 case options::OPT_fno_cx_limited_range:
@@ -3093,6 +3100,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
"-fno-cx-limited-range");
   }
   GccRangeComplexOption = "-fno-cx-limited-range";
+  LastComplexRangeOption = "-fno-cx-limited-range";
   Range = LangOptions::ComplexRangeKind::CX_Full;
   break;
 case options::OPT_fcx_fortran_rules:
@@ -3102,6 +3110,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   else
 EmitComplexRangeDiag(D, GccRangeComplexOption, "-fcx-fortran-rules");
   GccRangeComplexOption = "-fcx-fortran-rules";
+  LastComplexRangeOption = "-fcx-fortran-rules";
   Range = LangOptions::ComplexRangeKind::CX_Improved;
   break;
 case options::OPT_fno_cx_fortran_rules:
@@ -3114,6 +3123,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
"-fno-cx-fortran-rules");
   }
   GccRangeComplexOption = "-fno-cx-fortran-rules";
+  LastComplexRangeOption = "-fno-cx-fortran-rules";
   Range = LangOptions::ComplexRangeKind::CX_Full;
   break;
 case options::OPT_fcomplex_arithmetic_EQ: {
@@ -3148,6 +3158,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
  ComplexArithmeticStr(RangeVal));
 }
   }
+  LastComplexRangeOption = "-fcomplex-arithmetic";
   Range = RangeVal;
   break;
 }
@@ -3201,6 +3212,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   } else
 D.Diag(diag::err_drv_unsupported_option_argument)
 << A->getSpelling() << Val;
+  LastComplexRangeOption = "-ffp-model";
   break;
 }
 
@@ -3386,6 +3398,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   [[fallthrough]];
 case options::OPT_ffast_math:
   applyFastMath(true);
+  LastComplexRangeOption = "-ffast-math";
   if (A->getOption().getID() == options::OPT_Ofast)
 LastFpContractOverrideOption = "-Ofast";
   else
@@ -3403,6 +3416,13 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   ApproxFunc = false;
   SignedZeros = true;
   restoreFPContractState();
+  // If the last specified option related to complex range is -ffast-math,
+  // override 'Range' without warning.
+

[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-03-24 Thread Andy Kaylor via cfe-commits 


@@ -177,14 +177,45 @@
 // RUN: %clang -### -target x86_64 -ffast-math -fcomplex-arithmetic=basic -c 
%s 2>&1 \
 // RUN:   | FileCheck --check-prefix=BASIC %s
 
-// BASIC: -complex-range=basic
-// FULL: -complex-range=full
-// PRMTD: -complex-range=promoted
-// BASIC-NOT: -complex-range=improved
-// CHECK-NOT: -complex-range=basic
-// IMPRVD: -complex-range=improved
-// IMPRVD-NOT: -complex-range=basic
-// CHECK-NOT: -complex-range=improved
+// RUN: %clang -### -target x86_64 -fcx-limited-range -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN21 %s
+
+// RUN: %clang -### -Werror -target x86_64 -fno-cx-limited-range 
-fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL %s
+
+// RUN: %clang -### -target x86_64 -fcx-fortran-rules -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN22 %s
+
+// RUN: %clang -### -Werror -target x86_64 -fno-cx-fortran-rules 
-fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL %s
+
+// RUN: %clang -### -Werror -target x86_64 -ffast-math -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL %s
+
+// RUN: %clang -### -target x86_64 -fcomplex-arithmetic=basic -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN23 %s
+
+// RUN: %clang -### -target x86_64 -fcomplex-arithmetic=promoted 
-fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN24 %s
+
+// RUN: %clang -### -target x86_64 -fcomplex-arithmetic=improved 
-fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN25 %s
+
+// RUN: %clang -### -Werror -target x86_64 -fcomplex-arithmetic=full 
-fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL %s
+
+// RUN: %clang -### -target x86_64 -ffp-model=aggressive -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN23 %s
+
+// RUN: %clang -### -target x86_64 -ffp-model=fast -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL,WARN24 %s
+
+// RUN: %clang -### -Werror -target x86_64 -ffp-model=precise -fno-fast-math \
+// RUN: -c %s 2>&1 | FileCheck --check-prefixes=FULL %s
+
+// RUN: %clang -### -Werror -target x86_64 -ffp-model=strict -fno-fast-math \

andykaylor wrote:

Can you add test cases for when `-fno-fast-math` is followed by other options 
that change the complex mode?

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-03-24 Thread Andy Kaylor via cfe-commits 


@@ -2997,6 +2997,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   LangOptions::ComplexRangeKind Range = LangOptions::ComplexRangeKind::CX_None;
   std::string ComplexRangeStr = "";
   std::string GccRangeComplexOption = "";
+  std::string LastComplexRangeOption = "";

andykaylor wrote:

I don't think I remember during our Discourse discussion of this that there was 
already a `GccRangeComplexOption` variable here. Do we really need another 
variable? If you just set GccRangeComplexOption to empty for `-ffast-math` and 
`-fno-fast-math`, would that give us reasonable diagnostics?

https://github.com/llvm/llvm-project/pull/132680
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[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-03-24 Thread via cfe-commits 

llvmbot wrote:




@llvm/pr-subscribers-clang

Author: None (s-watanabe314)


Changes

…st-math

This patch fixes a bug where -fno-fast-math doesn't revert the complex number 
calculation method to the default. The priority of overriding options related 
to complex number calculations differs slightly from GCC, as discussed in:

https://discourse.llvm.org/t/the-priority-of-fno-fast-math-regarding-complex-number-calculations/84679

I will post another patch to add a warning that the option overriding rules are 
incompatible with GCC.
In that patch, I will also fix the conditions for warnings related to other 
complex number options.

---
Full diff: https://github.com/llvm/llvm-project/pull/132680.diff


2 Files Affected:

- (modified) clang/lib/Driver/ToolChains/Clang.cpp (+21-1) 
- (modified) clang/test/Driver/range.c (+53-8) 


``diff
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp 
b/clang/lib/Driver/ToolChains/Clang.cpp
index fb3ed2db0e3c0..484ced9885883 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -2997,6 +2997,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   LangOptions::ComplexRangeKind Range = LangOptions::ComplexRangeKind::CX_None;
   std::string ComplexRangeStr = "";
   std::string GccRangeComplexOption = "";
+  std::string LastComplexRangeOption = "";
 
   auto setComplexRange = [&](LangOptions::ComplexRangeKind NewRange) {
 // Warn if user expects to perform full implementation of complex
@@ -3015,7 +3016,12 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
 if (Aggressive) {
   HonorINFs = false;
   HonorNaNs = false;
-  setComplexRange(LangOptions::ComplexRangeKind::CX_Basic);
+  // If the last specified option related to complex range is
+  // -fno-fast-math, override 'Range' without warning.
+  if (LastComplexRangeOption == "-fno-fast-math")
+Range = LangOptions::ComplexRangeKind::CX_Basic;
+  else
+setComplexRange(LangOptions::ComplexRangeKind::CX_Basic);
 } else {
   HonorINFs = true;
   HonorNaNs = true;
@@ -3080,6 +3086,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   EmitComplexRangeDiag(D, GccRangeComplexOption, "-fcx-limited-range");
   }
   GccRangeComplexOption = "-fcx-limited-range";
+  LastComplexRangeOption = "-fcx-limited-range";
   Range = LangOptions::ComplexRangeKind::CX_Basic;
   break;
 case options::OPT_fno_cx_limited_range:
@@ -3093,6 +3100,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
"-fno-cx-limited-range");
   }
   GccRangeComplexOption = "-fno-cx-limited-range";
+  LastComplexRangeOption = "-fno-cx-limited-range";
   Range = LangOptions::ComplexRangeKind::CX_Full;
   break;
 case options::OPT_fcx_fortran_rules:
@@ -3102,6 +3110,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   else
 EmitComplexRangeDiag(D, GccRangeComplexOption, "-fcx-fortran-rules");
   GccRangeComplexOption = "-fcx-fortran-rules";
+  LastComplexRangeOption = "-fcx-fortran-rules";
   Range = LangOptions::ComplexRangeKind::CX_Improved;
   break;
 case options::OPT_fno_cx_fortran_rules:
@@ -3114,6 +3123,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
"-fno-cx-fortran-rules");
   }
   GccRangeComplexOption = "-fno-cx-fortran-rules";
+  LastComplexRangeOption = "-fno-cx-fortran-rules";
   Range = LangOptions::ComplexRangeKind::CX_Full;
   break;
 case options::OPT_fcomplex_arithmetic_EQ: {
@@ -3148,6 +3158,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
  ComplexArithmeticStr(RangeVal));
 }
   }
+  LastComplexRangeOption = "-fcomplex-arithmetic";
   Range = RangeVal;
   break;
 }
@@ -3201,6 +3212,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   } else
 D.Diag(diag::err_drv_unsupported_option_argument)
 << A->getSpelling() << Val;
+  LastComplexRangeOption = "-ffp-model";
   break;
 }
 
@@ -3386,6 +3398,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   [[fallthrough]];
 case options::OPT_ffast_math:
   applyFastMath(true);
+  LastComplexRangeOption = "-ffast-math";
   if (A->getOption().getID() == options::OPT_Ofast)
 LastFpContractOverrideOption = "-Ofast";
   else
@@ -3403,6 +3416,13 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   ApproxFunc = false;
   SignedZeros = true;
   restoreFPContractState();
+  // If the last specified option related to complex range is -ffast-math,
+  // override 'Range' without w

[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-03-24 Thread via cfe-commits 

llvmbot wrote:




@llvm/pr-subscribers-clang-driver

Author: None (s-watanabe314)


Changes

…st-math

This patch fixes a bug where -fno-fast-math doesn't revert the complex number 
calculation method to the default. The priority of overriding options related 
to complex number calculations differs slightly from GCC, as discussed in:

https://discourse.llvm.org/t/the-priority-of-fno-fast-math-regarding-complex-number-calculations/84679

I will post another patch to add a warning that the option overriding rules are 
incompatible with GCC.
In that patch, I will also fix the conditions for warnings related to other 
complex number options.

---
Full diff: https://github.com/llvm/llvm-project/pull/132680.diff


2 Files Affected:

- (modified) clang/lib/Driver/ToolChains/Clang.cpp (+21-1) 
- (modified) clang/test/Driver/range.c (+53-8) 


``diff
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp 
b/clang/lib/Driver/ToolChains/Clang.cpp
index fb3ed2db0e3c0..484ced9885883 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -2997,6 +2997,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   LangOptions::ComplexRangeKind Range = LangOptions::ComplexRangeKind::CX_None;
   std::string ComplexRangeStr = "";
   std::string GccRangeComplexOption = "";
+  std::string LastComplexRangeOption = "";
 
   auto setComplexRange = [&](LangOptions::ComplexRangeKind NewRange) {
 // Warn if user expects to perform full implementation of complex
@@ -3015,7 +3016,12 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
 if (Aggressive) {
   HonorINFs = false;
   HonorNaNs = false;
-  setComplexRange(LangOptions::ComplexRangeKind::CX_Basic);
+  // If the last specified option related to complex range is
+  // -fno-fast-math, override 'Range' without warning.
+  if (LastComplexRangeOption == "-fno-fast-math")
+Range = LangOptions::ComplexRangeKind::CX_Basic;
+  else
+setComplexRange(LangOptions::ComplexRangeKind::CX_Basic);
 } else {
   HonorINFs = true;
   HonorNaNs = true;
@@ -3080,6 +3086,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   EmitComplexRangeDiag(D, GccRangeComplexOption, "-fcx-limited-range");
   }
   GccRangeComplexOption = "-fcx-limited-range";
+  LastComplexRangeOption = "-fcx-limited-range";
   Range = LangOptions::ComplexRangeKind::CX_Basic;
   break;
 case options::OPT_fno_cx_limited_range:
@@ -3093,6 +3100,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
"-fno-cx-limited-range");
   }
   GccRangeComplexOption = "-fno-cx-limited-range";
+  LastComplexRangeOption = "-fno-cx-limited-range";
   Range = LangOptions::ComplexRangeKind::CX_Full;
   break;
 case options::OPT_fcx_fortran_rules:
@@ -3102,6 +3110,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   else
 EmitComplexRangeDiag(D, GccRangeComplexOption, "-fcx-fortran-rules");
   GccRangeComplexOption = "-fcx-fortran-rules";
+  LastComplexRangeOption = "-fcx-fortran-rules";
   Range = LangOptions::ComplexRangeKind::CX_Improved;
   break;
 case options::OPT_fno_cx_fortran_rules:
@@ -3114,6 +3123,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
"-fno-cx-fortran-rules");
   }
   GccRangeComplexOption = "-fno-cx-fortran-rules";
+  LastComplexRangeOption = "-fno-cx-fortran-rules";
   Range = LangOptions::ComplexRangeKind::CX_Full;
   break;
 case options::OPT_fcomplex_arithmetic_EQ: {
@@ -3148,6 +3158,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
  ComplexArithmeticStr(RangeVal));
 }
   }
+  LastComplexRangeOption = "-fcomplex-arithmetic";
   Range = RangeVal;
   break;
 }
@@ -3201,6 +3212,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   } else
 D.Diag(diag::err_drv_unsupported_option_argument)
 << A->getSpelling() << Val;
+  LastComplexRangeOption = "-ffp-model";
   break;
 }
 
@@ -3386,6 +3398,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   [[fallthrough]];
 case options::OPT_ffast_math:
   applyFastMath(true);
+  LastComplexRangeOption = "-ffast-math";
   if (A->getOption().getID() == options::OPT_Ofast)
 LastFpContractOverrideOption = "-Ofast";
   else
@@ -3403,6 +3416,13 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   ApproxFunc = false;
   SignedZeros = true;
   restoreFPContractState();
+  // If the last specified option related to complex range is -ffast-math,
+  // override 'Range' wi

[clang] [Clang][Driver] Override complex number calculation method by -fno-fa… (PR #132680)

2025-03-24 Thread via cfe-commits 

https://github.com/s-watanabe314 created 
https://github.com/llvm/llvm-project/pull/132680

…st-math

This patch fixes a bug where -fno-fast-math doesn't revert the complex number 
calculation method to the default. The priority of overriding options related 
to complex number calculations differs slightly from GCC, as discussed in:

https://discourse.llvm.org/t/the-priority-of-fno-fast-math-regarding-complex-number-calculations/84679

I will post another patch to add a warning that the option overriding rules are 
incompatible with GCC.
In that patch, I will also fix the conditions for warnings related to other 
complex number options.

>From 9265cb96cc3129fada722d7195a1cf04e985ba33 Mon Sep 17 00:00:00 2001
From: s-watanabe314 
Date: Fri, 14 Mar 2025 11:56:32 +0900
Subject: [PATCH] [Clang][Driver] Override complex number calculation method by
 -fno-fast-math

This patch fixes a bug where -fno-fast-math doesn't revert the complex
number calculation method to the default. The priority of overriding
options related to complex number calculations differs slightly from
GCC, as discussed in:

https://discourse.llvm.org/t/the-priority-of-fno-fast-math-regarding-complex-number-calculations/84679
---
 clang/lib/Driver/ToolChains/Clang.cpp | 22 +-
 clang/test/Driver/range.c | 61 +++
 2 files changed, 74 insertions(+), 9 deletions(-)

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp 
b/clang/lib/Driver/ToolChains/Clang.cpp
index fb3ed2db0e3c0..484ced9885883 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -2997,6 +2997,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   LangOptions::ComplexRangeKind Range = LangOptions::ComplexRangeKind::CX_None;
   std::string ComplexRangeStr = "";
   std::string GccRangeComplexOption = "";
+  std::string LastComplexRangeOption = "";
 
   auto setComplexRange = [&](LangOptions::ComplexRangeKind NewRange) {
 // Warn if user expects to perform full implementation of complex
@@ -3015,7 +3016,12 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
 if (Aggressive) {
   HonorINFs = false;
   HonorNaNs = false;
-  setComplexRange(LangOptions::ComplexRangeKind::CX_Basic);
+  // If the last specified option related to complex range is
+  // -fno-fast-math, override 'Range' without warning.
+  if (LastComplexRangeOption == "-fno-fast-math")
+Range = LangOptions::ComplexRangeKind::CX_Basic;
+  else
+setComplexRange(LangOptions::ComplexRangeKind::CX_Basic);
 } else {
   HonorINFs = true;
   HonorNaNs = true;
@@ -3080,6 +3086,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   EmitComplexRangeDiag(D, GccRangeComplexOption, "-fcx-limited-range");
   }
   GccRangeComplexOption = "-fcx-limited-range";
+  LastComplexRangeOption = "-fcx-limited-range";
   Range = LangOptions::ComplexRangeKind::CX_Basic;
   break;
 case options::OPT_fno_cx_limited_range:
@@ -3093,6 +3100,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
"-fno-cx-limited-range");
   }
   GccRangeComplexOption = "-fno-cx-limited-range";
+  LastComplexRangeOption = "-fno-cx-limited-range";
   Range = LangOptions::ComplexRangeKind::CX_Full;
   break;
 case options::OPT_fcx_fortran_rules:
@@ -3102,6 +3110,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   else
 EmitComplexRangeDiag(D, GccRangeComplexOption, "-fcx-fortran-rules");
   GccRangeComplexOption = "-fcx-fortran-rules";
+  LastComplexRangeOption = "-fcx-fortran-rules";
   Range = LangOptions::ComplexRangeKind::CX_Improved;
   break;
 case options::OPT_fno_cx_fortran_rules:
@@ -3114,6 +3123,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
"-fno-cx-fortran-rules");
   }
   GccRangeComplexOption = "-fno-cx-fortran-rules";
+  LastComplexRangeOption = "-fno-cx-fortran-rules";
   Range = LangOptions::ComplexRangeKind::CX_Full;
   break;
 case options::OPT_fcomplex_arithmetic_EQ: {
@@ -3148,6 +3158,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
  ComplexArithmeticStr(RangeVal));
 }
   }
+  LastComplexRangeOption = "-fcomplex-arithmetic";
   Range = RangeVal;
   break;
 }
@@ -3201,6 +3212,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   } else
 D.Diag(diag::err_drv_unsupported_option_argument)
 << A->getSpelling() << Val;
+  LastComplexRangeOption = "-ffp-model";
   break;
 }
 
@@ -3386,6 +3398,7 @@ static void RenderFloatingPointOptions(const ToolChain 
&TC, const Driver &D,
   [[fallthrough]]