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| author | Jakub Jelinek <jakub@redhat.com> | 2018-01-18 09:29:14 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2018-01-18 09:29:14 +0100 |
| commit | 8ae438811f695dd025fb1fef254bff920777b494 (patch) | |
| tree | 3ebe287328aa2352463c380f91f601c2002085b1 /gcc/match.pd | |
| parent | fcf7923742d34c0cb7270594d4cdab4ea1199672 (diff) | |
| download | gcc-8ae438811f695dd025fb1fef254bff920777b494.zip gcc-8ae438811f695dd025fb1fef254bff920777b494.tar.gz gcc-8ae438811f695dd025fb1fef254bff920777b494.tar.bz2 | |
re PR c/61240 (Incorrect warning "integer overflow in expression" on pointer-pointer subtraction)
PR c/61240
* match.pd ((P + A) - P, P - (P + A), (P + A) - (P + B)): For
pointer_diff optimizations use view_convert instead of convert.
* gcc.dg/pr61240.c: New test.
From-SVN: r256838
Diffstat (limited to 'gcc/match.pd')
| -rw-r--r-- | gcc/match.pd | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 3f6e009..b288a36 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -1832,7 +1832,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* The second argument of pointer_plus must be interpreted as signed, and thus sign-extended if necessary. */ (with { tree stype = signed_type_for (TREE_TYPE (@1)); } - (convert (convert:stype @1)))) + /* Use view_convert instead of convert here, as POINTER_PLUS_EXPR + second arg is unsigned even when we need to consider it as signed, + we don't want to diagnose overflow here. */ + (convert (view_convert:stype @1)))) /* (T)P - (T)(P + A) -> -(T) A */ (simplify @@ -1876,7 +1879,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* The second argument of pointer_plus must be interpreted as signed, and thus sign-extended if necessary. */ (with { tree stype = signed_type_for (TREE_TYPE (@1)); } - (negate (convert (convert:stype @1))))) + /* Use view_convert instead of convert here, as POINTER_PLUS_EXPR + second arg is unsigned even when we need to consider it as signed, + we don't want to diagnose overflow here. */ + (negate (convert (view_convert:stype @1))))) /* (T)(P + A) - (T)(P + B) -> (T)A - (T)B */ (simplify @@ -1927,7 +1933,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* The second argument of pointer_plus must be interpreted as signed, and thus sign-extended if necessary. */ (with { tree stype = signed_type_for (TREE_TYPE (@1)); } - (minus (convert (convert:stype @1)) (convert (convert:stype @2))))))) + /* Use view_convert instead of convert here, as POINTER_PLUS_EXPR + second arg is unsigned even when we need to consider it as signed, + we don't want to diagnose overflow here. */ + (minus (convert (view_convert:stype @1)) + (convert (view_convert:stype @2))))))) /* Simplifications of MIN_EXPR, MAX_EXPR, fmin() and fmax(). */ |