From 25879b97cff622cae8a56dddd34a1a79738a1993 Mon Sep 17 00:00:00 2001 From: Andrey Rachitskiy Date: Wed, 5 Aug 2026 09:02:47 +0500 Subject: [PATCH] Keep float8 overflow checks alive under gcc 13+ gcc 13+ jump threading can drop an isinf() overflow test in inlined float8_{pl,mi,mul,div} when both operands are proven finite, for example in circle_ar() after r*r with constant M_PI, or in nested pl(mul,mul). Report via non-noreturn float_*_error_ext() helpers so the checks are retained. float4_* are left unchanged. Add a geometry regress for area(circle) with radius 1e154. Bug: #19593 Author: Andrey Rachitskiy Reported-by: Michael Malis Discussion: https://www.postgresql.org/message-id/19593-d80bd21f90d32234%40postgresql.org --- src/backend/utils/adt/float.c | 24 ++++++++++++++++++++++++ src/include/utils/float.h | 19 +++++++++++++------ src/test/regress/expected/geometry.out | 3 +++ src/test/regress/sql/geometry.sql | 3 +++ 4 files changed, 43 insertions(+), 6 deletions(-) diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c index adb8c74cdde..c9bcc4da786 100644 --- a/src/backend/utils/adt/float.c +++ b/src/backend/utils/adt/float.c @@ -106,2 +106,26 @@ float_zero_divide_error(void) +/* + * Non-noreturn helpers for float8_{pl,mi,mul,div}. + * + * float_*_error() is noreturn. Calling it directly from those inlined + * helpers lets gcc 13+ jump threading drop a live isinf() check after + * proving both operands finite. Returning through these wrappers changes + * the CFG enough to keep that check. The return 0.0 is never executed + * (ereport does not return). It exists so the compiler sees an ordinary + * float8-returning call rather than a noreturn one. + */ +float8 +float_overflow_error_ext(void) +{ + float_overflow_error(); + return 0.0; +} + +float8 +float_underflow_error_ext(void) +{ + float_underflow_error(); + return 0.0; +} + diff --git a/src/include/utils/float.h b/src/include/utils/float.h index fcf7bd581bd..a34a8453e21 100644 --- a/src/include/utils/float.h +++ b/src/include/utils/float.h @@ -43,1 +43,3 @@ +extern float8 float_overflow_error_ext(void); +extern float8 float_underflow_error_ext(void); extern int is_infinite(float8 val); @@ -155,2 +157,7 @@ float4_pl(const float4 val1, const float4 val2) +/* + * float8_{pl,mi,mul,div} report via non-noreturn helpers. gcc 13+ jump + * threading may otherwise drop an isinf() check when both operands are + * proven finite (e.g. nested helpers after an earlier overflow check). + */ static inline float8 @@ -162,3 +169,3 @@ float8_pl(const float8 val1, const float8 val2) if (unlikely(isinf(result)) && !isinf(val1) && !isinf(val2)) - float_overflow_error(); + return float_overflow_error_ext(); @@ -186,3 +193,3 @@ float8_mi(const float8 val1, const float8 val2) if (unlikely(isinf(result)) && !isinf(val1) && !isinf(val2)) - float_overflow_error(); + return float_overflow_error_ext(); @@ -212,5 +219,5 @@ float8_mul(const float8 val1, const float8 val2) if (unlikely(isinf(result)) && !isinf(val1) && !isinf(val2)) - float_overflow_error(); + return float_overflow_error_ext(); if (unlikely(result == 0.0) && val1 != 0.0 && val2 != 0.0) - float_underflow_error(); + return float_underflow_error_ext(); @@ -244,5 +251,5 @@ float8_div(const float8 val1, const float8 val2) if (unlikely(isinf(result)) && !isinf(val1)) - float_overflow_error(); + return float_overflow_error_ext(); if (unlikely(result == 0.0) && val1 != 0.0 && !isinf(val2)) - float_underflow_error(); + return float_underflow_error_ext(); diff --git a/src/test/regress/expected/geometry.out b/src/test/regress/expected/geometry.out index 4bb1679157d..8ee277431ec 100644 --- a/src/test/regress/expected/geometry.out +++ b/src/test/regress/expected/geometry.out @@ -5137,2 +5137,5 @@ SELECT c.f1, p.f1, c.f1 / p.f1 FROM CIRCLE_TBL c, POINT_TBL p WHERE p.f1 ~= '(0, ERROR: division by zero +-- Overflow for radius 1e154 +SELECT area(circle '<(0,0),1e154>'); +ERROR: value out of range: overflow -- Distance to polygon diff --git a/src/test/regress/sql/geometry.sql b/src/test/regress/sql/geometry.sql index bbb6acd4555..081f2d160cd 100644 --- a/src/test/regress/sql/geometry.sql +++ b/src/test/regress/sql/geometry.sql @@ -510,2 +510,5 @@ SELECT c.f1, p.f1, c.f1 / p.f1 FROM CIRCLE_TBL c, POINT_TBL p WHERE p.f1 ~= '(0, +-- Overflow for radius 1e154 +SELECT area(circle '<(0,0),1e154>'); + -- Distance to polygon -- 2.53.0