From 4fb6aeb4f6e807c8ce3e140d2d2281f50eb6fb1a Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 20 Jul 2020 19:44:41 -0400 Subject: [PATCH] Make floating-point "NaN / 0" return NaN instead of raising an error. This is more consistent with the IEEE 754 spec and our treatment of NaNs elsewhere; in particular, the case has always acted that way in "numeric" arithmetic. Noted by Dean Rasheed. Discussion: https://postgr.es/m/3421746.1594927785@sss.pgh.pa.us --- src/include/utils/float.h | 4 ++-- src/test/regress/expected/float4-misrounded-input.out | 6 ++++++ src/test/regress/expected/float4.out | 6 ++++++ src/test/regress/expected/float8.out | 6 ++++++ src/test/regress/sql/float4.sql | 1 + src/test/regress/sql/float8.sql | 1 + 6 files changed, 22 insertions(+), 2 deletions(-) diff --git a/src/include/utils/float.h b/src/include/utils/float.h index 8d4bbc51a6..e2aae8ef17 100644 --- a/src/include/utils/float.h +++ b/src/include/utils/float.h @@ -222,7 +222,7 @@ float4_div(const float4 val1, const float4 val2) { float4 result; - if (unlikely(val2 == 0.0f)) + if (unlikely(val2 == 0.0f) && !isnan(val1)) float_zero_divide_error(); result = val1 / val2; if (unlikely(isinf(result)) && !isinf(val1) && !isinf(val2)) @@ -238,7 +238,7 @@ float8_div(const float8 val1, const float8 val2) { float8 result; - if (unlikely(val2 == 0.0)) + if (unlikely(val2 == 0.0) && !isnan(val1)) float_zero_divide_error(); result = val1 / val2; if (unlikely(isinf(result)) && !isinf(val1) && !isinf(val2)) diff --git a/src/test/regress/expected/float4-misrounded-input.out b/src/test/regress/expected/float4-misrounded-input.out index 6c89af6394..38b847a1ad 100644 --- a/src/test/regress/expected/float4-misrounded-input.out +++ b/src/test/regress/expected/float4-misrounded-input.out @@ -143,6 +143,12 @@ SELECT 'nan'::float4 / 'nan'::float4; NaN (1 row) +SELECT 'nan'::float4 / '0'::float4; + ?column? +---------- + NaN +(1 row) + SELECT 'nan'::numeric::float4; float4 -------- diff --git a/src/test/regress/expected/float4.out b/src/test/regress/expected/float4.out index d6c22c1752..310402b6ee 100644 --- a/src/test/regress/expected/float4.out +++ b/src/test/regress/expected/float4.out @@ -143,6 +143,12 @@ SELECT 'nan'::float4 / 'nan'::float4; NaN (1 row) +SELECT 'nan'::float4 / '0'::float4; + ?column? +---------- + NaN +(1 row) + SELECT 'nan'::numeric::float4; float4 -------- diff --git a/src/test/regress/expected/float8.out b/src/test/regress/expected/float8.out index c635dd7dcb..2304b579d2 100644 --- a/src/test/regress/expected/float8.out +++ b/src/test/regress/expected/float8.out @@ -126,6 +126,12 @@ SELECT 'nan'::float8 / 'nan'::float8; NaN (1 row) +SELECT 'nan'::float8 / '0'::float8; + ?column? +---------- + NaN +(1 row) + SELECT 'nan'::numeric::float8; float8 -------- diff --git a/src/test/regress/sql/float4.sql b/src/test/regress/sql/float4.sql index 393d98fb14..1fcf823c21 100644 --- a/src/test/regress/sql/float4.sql +++ b/src/test/regress/sql/float4.sql @@ -50,6 +50,7 @@ SELECT ' INFINITY x'::float4; SELECT 'Infinity'::float4 + 100.0; SELECT 'Infinity'::float4 / 'Infinity'::float4; SELECT 'nan'::float4 / 'nan'::float4; +SELECT 'nan'::float4 / '0'::float4; SELECT 'nan'::numeric::float4; SELECT '' AS five, * FROM FLOAT4_TBL; diff --git a/src/test/regress/sql/float8.sql b/src/test/regress/sql/float8.sql index 288969aed6..f103871cdb 100644 --- a/src/test/regress/sql/float8.sql +++ b/src/test/regress/sql/float8.sql @@ -43,6 +43,7 @@ SELECT ' INFINITY x'::float8; SELECT 'Infinity'::float8 + 100.0; SELECT 'Infinity'::float8 / 'Infinity'::float8; SELECT 'nan'::float8 / 'nan'::float8; +SELECT 'nan'::float8 / '0'::float8; SELECT 'nan'::numeric::float8; SELECT '' AS five, * FROM FLOAT8_TBL;