| Message ID | ZfQJlBjlIcp+5kEY@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | expand: EXTEND_BITINT CALL_EXPR results [PR114332] | expand |
On Fri, 15 Mar 2024, Jakub Jelinek wrote: > Hi! > > The x86-64 and aarch64 psABIs (and the unwritten ia64 psABI part) say that > the padding bits of _BitInt are undefined, while the expansion internally > typically assumes that non-mode precision integers are sign/zero extended > and extends after operations. We handle that mismatch with EXTEND_BITINT > done when reading from untrusted sources like function arguments, reading > _BitInt from memory etc. but otherwise keep relying on stuff being extended > internally (say in pseudos). > The return value of a function is an ABI boundary though too and we need > to extend that too. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? OK. > 2024-03-15 Jakub Jelinek <jakub@redhat.com> > > PR middle-end/114332 > * expr.cc (expand_expr_real_1): EXTEND_BITINT also CALL_EXPR results. > > --- gcc/expr.cc.jj 2024-03-04 19:20:27.120200885 +0100 > +++ gcc/expr.cc 2024-03-14 19:22:50.623550538 +0100 > @@ -12350,7 +12350,8 @@ expand_expr_real_1 (tree exp, rtx target > return expand_builtin (exp, target, subtarget, tmode, ignore); > } > } > - return expand_call (exp, target, ignore); > + temp = expand_call (exp, target, ignore); > + return EXTEND_BITINT (temp); > > case VIEW_CONVERT_EXPR: > op0 = NULL_RTX; > --- gcc/testsuite/gcc.dg/torture/bitint-64.c.jj 2024-03-14 19:50:41.051311949 +0100 > +++ gcc/testsuite/gcc.dg/torture/bitint-64.c 2024-03-14 19:50:05.480806808 +0100 > @@ -0,0 +1,22 @@ > +/* PR middle-end/114332 */ > +/* { dg-do run { target bitint } } */ > +/* { dg-options "-std=c23 -fwrapv" } */ > +/* { dg-skip-if "" { ! run_expensive_tests } { "*" } { "-O0" "-O2" } } */ > +/* { dg-skip-if "" { ! run_expensive_tests } { "-flto" } { "" } } */ > + > +enum E { E22 = 22 } e = E22; > + > +_BitInt (5) > +foo (void) > +{ > + _Atomic _BitInt (5) b = 0; > + b += e; > + return b; > +} > + > +int > +main () > +{ > + if (foo () != -10) > + __builtin_abort (); > +} > > Jakub > >
--- gcc/expr.cc.jj 2024-03-04 19:20:27.120200885 +0100 +++ gcc/expr.cc 2024-03-14 19:22:50.623550538 +0100 @@ -12350,7 +12350,8 @@ expand_expr_real_1 (tree exp, rtx target return expand_builtin (exp, target, subtarget, tmode, ignore); } } - return expand_call (exp, target, ignore); + temp = expand_call (exp, target, ignore); + return EXTEND_BITINT (temp); case VIEW_CONVERT_EXPR: op0 = NULL_RTX; --- gcc/testsuite/gcc.dg/torture/bitint-64.c.jj 2024-03-14 19:50:41.051311949 +0100 +++ gcc/testsuite/gcc.dg/torture/bitint-64.c 2024-03-14 19:50:05.480806808 +0100 @@ -0,0 +1,22 @@ +/* PR middle-end/114332 */ +/* { dg-do run { target bitint } } */ +/* { dg-options "-std=c23 -fwrapv" } */ +/* { dg-skip-if "" { ! run_expensive_tests } { "*" } { "-O0" "-O2" } } */ +/* { dg-skip-if "" { ! run_expensive_tests } { "-flto" } { "" } } */ + +enum E { E22 = 22 } e = E22; + +_BitInt (5) +foo (void) +{ + _Atomic _BitInt (5) b = 0; + b += e; + return b; +} + +int +main () +{ + if (foo () != -10) + __builtin_abort (); +}