[PATCH] PR middle-end/53267: Constant fold BUILT_IN_FMOD.

gcc/ChangeLog
	PR middle-end/53267
	* fold-const-call.c (fold_const_call_sss) [CASE_CFN_FMOD]:
	Support evaluation of fmod/fmodf/fmodl at compile-time.

gcc/testsuite/ChangeLog
	* gcc.dg/builtins-70.c: New test.

diff --git a/gcc/fold-const-call.c b/gcc/fold-const-call.c
index a1d70b6..d6cb9b1 100644 (file)
--- a/gcc/fold-const-call.c
+++ b/gcc/fold-const-call.c
@@ -1375,6 +1375,9 @@ fold_const_call_sss (real_value *result, combined_fn fn,
     CASE_CFN_FDIM:
       return do_mpfr_arg2 (result, mpfr_dim, arg0, arg1, format);
 
+    CASE_CFN_FMOD:
+      return do_mpfr_arg2 (result, mpfr_fmod, arg0, arg1, format);
+
     CASE_CFN_HYPOT:
       return do_mpfr_arg2 (result, mpfr_hypot, arg0, arg1, format);
 

diff --git a/gcc/testsuite/gcc.dg/builtins-70.c b/gcc/testsuite/gcc.dg/builtins-70.c
new file mode 100644 (file)
index 0000000..a0c2dc9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/builtins-70.c
@@ -0,0 +1,46 @@
+/* Copyright (C) 2021 Free Software Foundation.
+
+   Check that constant folding of built-in fmod functions doesn't
+   break anything and produces the expected results.
+
+/* { dg-do link } */
+/* { dg-options "-O2 -ffast-math" } */
+
+extern void link_error(void);
+
+extern double fmod(double,double);
+extern float fmodf(float,float);
+extern long double fmodl(long double,long double);
+
+int main()
+{
+  if (fmod (6.5, 2.3) < 1.8999 || fmod (6.5, 2.3) > 1.9001)
+    link_error ();
+  if (fmod (-6.5, 2.3) < -1.9001 || fmod (-6.5, 2.3) > -1.8999)
+    link_error ();
+  if (fmod (6.5, -2.3) < 1.8999 || fmod (6.5, -2.3) > 1.9001)
+    link_error ();
+  if (fmod (-6.5, -2.3) < -1.9001 || fmod (-6.5, -2.3) > -1.8999)
+    link_error ();
+
+  if (fmodf (6.5f, 2.3f) < 1.8999f || fmodf (6.5f, 2.3f) > 1.9001f)
+    link_error ();
+  if (fmodf (-6.5f, 2.3f) < -1.9001f || fmodf (-6.5f, 2.3f) > -1.8999f)
+    link_error ();
+  if (fmodf (6.5f, -2.3f) < 1.8999f || fmodf (6.5f, -2.3f) > 1.9001f)
+    link_error ();
+  if (fmodf (-6.5f, -2.3f) < -1.9001f || fmodf (-6.5f, -2.3f) > -1.8999f)
+    link_error ();
+
+  if (fmodl (6.5l, 2.3l) < 1.8999l || fmod (6.5l, 2.3l) > 1.9001l)
+    link_error ();
+  if (fmodl (-6.5l, 2.3l) < -1.9001l || fmod (-6.5l, 2.3l) > -1.8999l)
+    link_error ();
+  if (fmodl (6.5l, -2.3l) < 1.8999l || fmod (6.5l, -2.3l) > 1.9001l)
+    link_error ();
+  if (fmodl (-6.5l, -2.3l) < -1.9001l || fmod (-6.5l, -2.3l) > -1.8999l)
+    link_error ();
+
+  return 0;
+}
+