[gcc r12-3715] c-family: Add more predefined macros for math flags

[gcc r12-3715] c-family: Add more predefined macros for math flags

[Matthias Kretz]

https://gcc.gnu.org/g:1949d7540a0322993bcae2f8893e2dbd29209040

commit r12-3715-g1949d7540a0322993bcae2f8893e2dbd29209040
Author: Matthias Kretz <m.kretz@gsi.de>
Date:   Wed Jun 30 10:41:33 2021 +0200

    c-family: Add more predefined macros for math flags
    
    Library code, especially in headers, sometimes needs to know how the
    compiler interprets / optimizes floating-point types and operations.
    This information can be used for additional optimizations or for
    ensuring correctness. This change makes -freciprocal-math,
    -fno-signed-zeros, -fno-trapping-math, -fassociative-math, and
    -frounding-math report their state via corresponding pre-defined macros.
    
    Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
    
    gcc/testsuite/ChangeLog:
    
            * gcc.dg/associative-math-1.c: New test.
            * gcc.dg/associative-math-2.c: New test.
            * gcc.dg/no-signed-zeros-1.c: New test.
            * gcc.dg/no-signed-zeros-2.c: New test.
            * gcc.dg/no-trapping-math-1.c: New test.
            * gcc.dg/no-trapping-math-2.c: New test.
            * gcc.dg/reciprocal-math-1.c: New test.
            * gcc.dg/reciprocal-math-2.c: New test.
            * gcc.dg/rounding-math-1.c: New test.
            * gcc.dg/rounding-math-2.c: New test.
    
    gcc/c-family/ChangeLog:
    
            * c-cppbuiltin.c (c_cpp_builtins_optimize_pragma): Define or
            undefine __RECIPROCAL_MATH__, __NO_SIGNED_ZEROS__,
            __NO_TRAPPING_MATH__, __ASSOCIATIVE_MATH__, and
            __ROUNDING_MATH__ according to the new optimization flags.
    
    gcc/ChangeLog:
    
            * cppbuiltin.c (define_builtin_macros_for_compilation_flags):
            Define __RECIPROCAL_MATH__, __NO_SIGNED_ZEROS__,
            __NO_TRAPPING_MATH__, __ASSOCIATIVE_MATH__, and
            __ROUNDING_MATH__ according to their corresponding flags.
            * doc/cpp.texi: Document __RECIPROCAL_MATH__,
            __NO_SIGNED_ZEROS__, __NO_TRAPPING_MATH__, __ASSOCIATIVE_MATH__,
            and __ROUNDING_MATH__.

Diff:
---
 gcc/c-family/c-cppbuiltin.c               | 25 +++++++++++++++++++++++++
 gcc/cppbuiltin.c                          | 10 ++++++++++
 gcc/doc/cpp.texi                          | 18 ++++++++++++++++++
 gcc/testsuite/gcc.dg/associative-math-1.c | 17 +++++++++++++++++
 gcc/testsuite/gcc.dg/associative-math-2.c | 17 +++++++++++++++++
 gcc/testsuite/gcc.dg/no-signed-zeros-1.c  | 17 +++++++++++++++++
 gcc/testsuite/gcc.dg/no-signed-zeros-2.c  | 17 +++++++++++++++++
 gcc/testsuite/gcc.dg/no-trapping-math-1.c | 17 +++++++++++++++++
 gcc/testsuite/gcc.dg/no-trapping-math-2.c | 17 +++++++++++++++++
 gcc/testsuite/gcc.dg/reciprocal-math-1.c  | 17 +++++++++++++++++
 gcc/testsuite/gcc.dg/reciprocal-math-2.c  | 17 +++++++++++++++++
 gcc/testsuite/gcc.dg/rounding-math-1.c    | 17 +++++++++++++++++
 gcc/testsuite/gcc.dg/rounding-math-2.c    | 17 +++++++++++++++++
 13 files changed, 223 insertions(+)

diff --git a/gcc/c-family/c-cppbuiltin.c b/gcc/c-family/c-cppbuiltin.c
index ce88e707127..a2992733114 100644
--- a/gcc/c-family/c-cppbuiltin.c
+++ b/gcc/c-family/c-cppbuiltin.c
@@ -628,6 +628,31 @@ c_cpp_builtins_optimize_pragma (cpp_reader *pfile, tree prev_tree,
       cpp_undef (pfile, "__FINITE_MATH_ONLY__");
       cpp_define_unused (pfile, "__FINITE_MATH_ONLY__=0");
     }
+
+  if (!prev->x_flag_reciprocal_math && cur->x_flag_reciprocal_math)
+    cpp_define_unused (pfile, "__RECIPROCAL_MATH__");
+  else if (prev->x_flag_reciprocal_math && !cur->x_flag_reciprocal_math)
+    cpp_undef (pfile, "__RECIPROCAL_MATH__");
+
+  if (!prev->x_flag_signed_zeros && cur->x_flag_signed_zeros)
+    cpp_undef (pfile, "__NO_SIGNED_ZEROS__");
+  else if (prev->x_flag_signed_zeros && !cur->x_flag_signed_zeros)
+    cpp_define_unused (pfile, "__NO_SIGNED_ZEROS__");
+
+  if (!prev->x_flag_trapping_math && cur->x_flag_trapping_math)
+    cpp_undef (pfile, "__NO_TRAPPING_MATH__");
+  else if (prev->x_flag_trapping_math && !cur->x_flag_trapping_math)
+    cpp_define_unused (pfile, "__NO_TRAPPING_MATH__");
+
+  if (!prev->x_flag_associative_math && cur->x_flag_associative_math)
+    cpp_define_unused (pfile, "__ASSOCIATIVE_MATH__");
+  else if (prev->x_flag_associative_math && !cur->x_flag_associative_math)
+    cpp_undef (pfile, "__ASSOCIATIVE_MATH__");
+
+  if (!prev->x_flag_rounding_math && cur->x_flag_rounding_math)
+    cpp_define_unused (pfile, "__ROUNDING_MATH__");
+  else if (prev->x_flag_rounding_math && !cur->x_flag_rounding_math)
+    cpp_undef (pfile, "__ROUNDING_MATH__");
 }
 
 
diff --git a/gcc/cppbuiltin.c b/gcc/cppbuiltin.c
index 2c6bcfa92cf..e112ee83283 100644
--- a/gcc/cppbuiltin.c
+++ b/gcc/cppbuiltin.c
@@ -110,6 +110,16 @@ define_builtin_macros_for_compilation_flags (cpp_reader *pfile)
     cpp_define (pfile, "__SUPPORT_SNAN__");
   if (!flag_errno_math)
     cpp_define (pfile, "__NO_MATH_ERRNO__");
+  if (flag_reciprocal_math)
+    cpp_define (pfile, "__RECIPROCAL_MATH__");
+  if (!flag_signed_zeros)
+    cpp_define (pfile, "__NO_SIGNED_ZEROS__");
+  if (!flag_trapping_math)
+    cpp_define (pfile, "__NO_TRAPPING_MATH__");
+  if (flag_associative_math)
+    cpp_define (pfile, "__ASSOCIATIVE_MATH__");
+  if (flag_rounding_math)
+    cpp_define (pfile, "__ROUNDING_MATH__");
 
   cpp_define_formatted (pfile, "__FINITE_MATH_ONLY__=%d",
 			flag_finite_math_only);
diff --git a/gcc/doc/cpp.texi b/gcc/doc/cpp.texi
index d4b3ff0a8b0..53f7204504c 100644
--- a/gcc/doc/cpp.texi
+++ b/gcc/doc/cpp.texi
@@ -2462,6 +2462,24 @@ features are supported by GCC.
 This macro is defined if @option{-fno-math-errno} is used, or enabled
 by another option such as @option{-ffast-math} or by default.
 
+@item __RECIPROCAL_MATH__
+This macro is defined if @option{-freciprocal-math} is used, or enabled
+by another option such as @option{-ffast-math} or by default.
+
+@item __NO_SIGNED_ZEROS__
+This macro is defined if @option{-fno-signed-zeros} is used, or enabled
+by another option such as @option{-ffast-math} or by default.
+
+@item __NO_TRAPPING_MATH__
+This macro is defined if @option{-fno-trapping-math} is used.
+
+@item __ASSOCIATIVE_MATH__
+This macro is defined if @option{-fassociative-math} is used, or enabled
+by another option such as @option{-ffast-math} or by default.
+
+@item __ROUNDING_MATH__
+This macro is defined if @option{-frounding-math} is used.
+
 @item __GNUC_EXECUTION_CHARSET_NAME
 @itemx __GNUC_WIDE_EXECUTION_CHARSET_NAME
 These macros are defined to expand to a narrow string literal of
diff --git a/gcc/testsuite/gcc.dg/associative-math-1.c b/gcc/testsuite/gcc.dg/associative-math-1.c
new file mode 100644
index 00000000000..3f9ce5b4bf7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/associative-math-1.c
@@ -0,0 +1,17 @@
+/* Test __ASSOCIATIVE_MATH__ is defined with -fassociative-math.  */
+/* { dg-do compile } */
+/* { dg-options "-fassociative-math -fno-signed-zeros -fno-trapping-math" } */
+
+#ifndef __ASSOCIATIVE_MATH__
+#error "__ASSOCIATIVE_MATH__ not defined"
+#endif
+
+#pragma GCC optimize "-fno-associative-math"
+#ifdef __ASSOCIATIVE_MATH__
+#error "__ASSOCIATIVE_MATH__ defined"
+#endif
+
+#pragma GCC optimize "-fassociative-math"
+#ifndef __ASSOCIATIVE_MATH__
+#error "__ASSOCIATIVE_MATH__ not defined"
+#endif
diff --git a/gcc/testsuite/gcc.dg/associative-math-2.c b/gcc/testsuite/gcc.dg/associative-math-2.c
new file mode 100644
index 00000000000..764d6f01bdb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/associative-math-2.c
@@ -0,0 +1,17 @@
+/* Test __ASSOCIATIVE_MATH__ is not defined with -fno-associative-math.  */
+/* { dg-do compile } */
+/* { dg-options "-fno-associative-math" } */
+
+#ifdef __ASSOCIATIVE_MATH__
+#error "__ASSOCIATIVE_MATH__ defined"
+#endif
+
+#pragma GCC optimize "-fassociative-math"
+#ifndef __ASSOCIATIVE_MATH__
+#error "__ASSOCIATIVE_MATH__ not defined"
+#endif
+
+#pragma GCC optimize "-fno-associative-math"
+#ifdef __ASSOCIATIVE_MATH__
+#error "__ASSOCIATIVE_MATH__ defined"
+#endif
diff --git a/gcc/testsuite/gcc.dg/no-signed-zeros-1.c b/gcc/testsuite/gcc.dg/no-signed-zeros-1.c
new file mode 100644
index 00000000000..3b9cd71c84f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/no-signed-zeros-1.c
@@ -0,0 +1,17 @@
+/* Test __NO_SIGNED_ZEROS__ is defined with -fno-signed-zeros.  */
+/* { dg-do compile } */
+/* { dg-options "-fno-signed-zeros" } */
+
+#ifndef __NO_SIGNED_ZEROS__
+#error "__NO_SIGNED_ZEROS__ not defined"
+#endif
+
+#pragma GCC optimize "-fsigned-zeros"
+#ifdef __NO_SIGNED_ZEROS__
+#error "__NO_SIGNED_ZEROS__ defined"
+#endif
+
+#pragma GCC optimize "-fno-signed-zeros"
+#ifndef __NO_SIGNED_ZEROS__
+#error "__NO_SIGNED_ZEROS__ not defined"
+#endif
diff --git a/gcc/testsuite/gcc.dg/no-signed-zeros-2.c b/gcc/testsuite/gcc.dg/no-signed-zeros-2.c
new file mode 100644
index 00000000000..865a29f6863
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/no-signed-zeros-2.c
@@ -0,0 +1,17 @@
+/* Test __NO_SIGNED_ZEROS__ is not defined with -fsigned-zeros.  */
+/* { dg-do compile } */
+/* { dg-options "-fsigned-zeros" } */
+
+#ifdef __NO_SIGNED_ZEROS__
+#error "__NO_SIGNED_ZEROS__ defined"
+#endif
+
+#pragma GCC optimize "-fno-signed-zeros"
+#ifndef __NO_SIGNED_ZEROS__
+#error "__NO_SIGNED_ZEROS__ not defined"
+#endif
+
+#pragma GCC optimize "-fsigned-zeros"
+#ifdef __NO_SIGNED_ZEROS__
+#error "__NO_SIGNED_ZEROS__ defined"
+#endif
diff --git a/gcc/testsuite/gcc.dg/no-trapping-math-1.c b/gcc/testsuite/gcc.dg/no-trapping-math-1.c
new file mode 100644
index 00000000000..f4faec9a7a3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/no-trapping-math-1.c
@@ -0,0 +1,17 @@
+/* Test __NO_TRAPPING_MATH__ is defined with -fno-trapping-math.  */
+/* { dg-do compile } */
+/* { dg-options "-fno-trapping-math" } */
+
+#ifndef __NO_TRAPPING_MATH__
+#error "__NO_TRAPPING_MATH__ not defined"
+#endif
+
+#pragma GCC optimize "-ftrapping-math"
+#ifdef __NO_TRAPPING_MATH__
+#error "__NO_TRAPPING_MATH__ defined"
+#endif
+
+#pragma GCC optimize "-fno-trapping-math"
+#ifndef __NO_TRAPPING_MATH__
+#error "__NO_TRAPPING_MATH__ not defined"
+#endif
diff --git a/gcc/testsuite/gcc.dg/no-trapping-math-2.c b/gcc/testsuite/gcc.dg/no-trapping-math-2.c
new file mode 100644
index 00000000000..1904b5db453
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/no-trapping-math-2.c
@@ -0,0 +1,17 @@
+/* Test __NO_TRAPPING_MATH__ is not defined with -ftrapping-math.  */
+/* { dg-do compile } */
+/* { dg-options "-ftrapping-math" } */
+
+#ifdef __NO_TRAPPING_MATH__
+#error "__NO_TRAPPING_MATH__ defined"
+#endif
+
+#pragma GCC optimize "-fno-trapping-math"
+#ifndef __NO_TRAPPING_MATH__
+#error "__NO_TRAPPING_MATH__ not defined"
+#endif
+
+#pragma GCC optimize "-ftrapping-math"
+#ifdef __NO_TRAPPING_MATH__
+#error "__NO_TRAPPING_MATH__ defined"
+#endif
diff --git a/gcc/testsuite/gcc.dg/reciprocal-math-1.c b/gcc/testsuite/gcc.dg/reciprocal-math-1.c
new file mode 100644
index 00000000000..49173e23166
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/reciprocal-math-1.c
@@ -0,0 +1,17 @@
+/* Test __RECIPROCAL_MATH__ is defined with -freciprocal-math.  */
+/* { dg-do compile } */
+/* { dg-options "-freciprocal-math" } */
+
+#ifndef __RECIPROCAL_MATH__
+#error "__RECIPROCAL_MATH__ not defined"
+#endif
+
+#pragma GCC optimize "-fno-reciprocal-math"
+#ifdef __RECIPROCAL_MATH__
+#error "__RECIPROCAL_MATH__ defined"
+#endif
+
+#pragma GCC optimize "-freciprocal-math"
+#ifndef __RECIPROCAL_MATH__
+#error "__RECIPROCAL_MATH__ not defined"
+#endif
diff --git a/gcc/testsuite/gcc.dg/reciprocal-math-2.c b/gcc/testsuite/gcc.dg/reciprocal-math-2.c
new file mode 100644
index 00000000000..959baa794b0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/reciprocal-math-2.c
@@ -0,0 +1,17 @@
+/* Test __RECIPROCAL_MATH__ is not defined with -fno-reciprocal-math.  */
+/* { dg-do compile } */
+/* { dg-options "-fno-reciprocal-math" } */
+
+#ifdef __RECIPROCAL_MATH__
+#error "__RECIPROCAL_MATH__ defined"
+#endif
+
+#pragma GCC optimize "-freciprocal-math"
+#ifndef __RECIPROCAL_MATH__
+#error "__RECIPROCAL_MATH__ not defined"
+#endif
+
+#pragma GCC optimize "-fno-reciprocal-math"
+#ifdef __RECIPROCAL_MATH__
+#error "__RECIPROCAL_MATH__ defined"
+#endif
diff --git a/gcc/testsuite/gcc.dg/rounding-math-1.c b/gcc/testsuite/gcc.dg/rounding-math-1.c
new file mode 100644
index 00000000000..3b13549e48a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/rounding-math-1.c
@@ -0,0 +1,17 @@
+/* Test __ROUNDING_MATH__ is defined with -frounding-math.  */
+/* { dg-do compile } */
+/* { dg-options "-frounding-math" } */
+
+#ifndef __ROUNDING_MATH__
+#error "__ROUNDING_MATH__ not defined"
+#endif
+
+#pragma GCC optimize "-fno-rounding-math"
+#ifdef __ROUNDING_MATH__
+#error "__ROUNDING_MATH__ defined"
+#endif
+
+#pragma GCC optimize "-frounding-math"
+#ifndef __ROUNDING_MATH__
+#error "__ROUNDING_MATH__ not defined"
+#endif
diff --git a/gcc/testsuite/gcc.dg/rounding-math-2.c b/gcc/testsuite/gcc.dg/rounding-math-2.c
new file mode 100644
index 00000000000..6468a84c4c7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/rounding-math-2.c
@@ -0,0 +1,17 @@
+/* Test __ROUNDING_MATH__ is not defined with -fno-rounding-math.  */
+/* { dg-do compile } */
+/* { dg-options "-fno-rounding-math" } */
+
+#ifdef __ROUNDING_MATH__
+#error "__ROUNDING_MATH__ defined"
+#endif
+
+#pragma GCC optimize "-frounding-math"
+#ifndef __ROUNDING_MATH__
+#error "__ROUNDING_MATH__ not defined"
+#endif
+
+#pragma GCC optimize "-fno-rounding-math"
+#ifdef __ROUNDING_MATH__
+#error "__ROUNDING_MATH__ defined"
+#endif