From cbd2a10dd9edadb262934aed64c0959339da68d1 Mon Sep 17 00:00:00 2001 From: Haijian Zhang Date: Fri, 24 Apr 2020 08:56:25 +0800 Subject: [PATCH] rtl combine should consider NaNs when generate fp min/max [PR94708] As discussed on PR94708, it's unsafe for rtl combine to generate fp min/max under -funsafe-math-optimizations, considering NaNs. In addition to flag_unsafe_math_optimizations check, we also need to do extra mode feature testing here: && !HONOR_NANS (mode) && !HONOR_SIGNED_ZEROS (mode) 2020-04-24 Haijian Zhang gcc/ PR rtl-optimization/94708 * combine.c (simplify_if_then_else): Add check for !HONOR_NANS (mode) && !HONOR_SIGNED_ZEROS (mode). gcc/testsuite/ PR fortran/94708 * gfortran.dg/pr94708.f90: New test. --- gcc/ChangeLog | 6 ++++++ gcc/combine.c | 5 ++++- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gfortran.dg/pr94708.f90 | 13 +++++++++++++ 4 files changed, 28 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gfortran.dg/pr94708.f90 diff --git a/gcc/ChangeLog b/gcc/ChangeLog index cf97cfed626..6032e681d7f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2020-04-24 Haijian Zhang + + PR rtl-optimization/94708 + * combine.c (simplify_if_then_else): Add check for + !HONOR_NANS (mode) && !HONOR_SIGNED_ZEROS (mode). + 2020-04-23 Martin Sebor PR driver/90983 diff --git a/gcc/combine.c b/gcc/combine.c index cff76cd3303..4c324f38660 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -6643,7 +6643,10 @@ simplify_if_then_else (rtx x) /* Look for MIN or MAX. */ - if ((! FLOAT_MODE_P (mode) || flag_unsafe_math_optimizations) + if ((! FLOAT_MODE_P (mode) + || (flag_unsafe_math_optimizations + && !HONOR_NANS (mode) + && !HONOR_SIGNED_ZEROS (mode))) && comparison_p && rtx_equal_p (XEXP (cond, 0), true_rtx) && rtx_equal_p (XEXP (cond, 1), false_rtx) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index a955cd5f4f8..4b1e9e11e7c 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-04-24 Haijian Zhang + + PR rtl-optimization/94708 + * gfortran.dg/pr94708.f90: New test. + 2020-04-23 David Edelsohn * gcc.dg/torture/pr90020.c: Skip on AIX. diff --git a/gcc/testsuite/gfortran.dg/pr94708.f90 b/gcc/testsuite/gfortran.dg/pr94708.f90 new file mode 100644 index 00000000000..9b5f1389f09 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/pr94708.f90 @@ -0,0 +1,13 @@ +! { dg-do compile { target aarch64*-*-* } } +! { dg-options "-O2 -funsafe-math-optimizations -fdump-rtl-combine" } + +subroutine f(vara,varb,varc,res) + REAL, INTENT(IN) :: vara,varb,varc + REAL, INTENT(out) :: res + + res = vara + if (res .lt. varb) res = varb + if (res .gt. varc) res = varc +end subroutine + +! { dg-final { scan-rtl-dump-not "smin" "combine" } } -- 2.30.2