| Message ID | CABKRkgjqsRUyH+c_yWgaQfzo4a-aBxqQdG+Hb07eeJVNgMok-w@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [PR91504] Inlining misses some logical operation folding | expand |
On Mon, 26 Aug 2019, kamlesh kumar wrote: > 2019-08-26 Kamlesh Kumar <kamleshbhalui@gmail.com> > > * gcc/match.pd: Added simplification > pattern. > * gcc.dg/tree-ssa/pr91504.c: New test. > ==================== > > diff --git a/gcc/match.pd b/gcc/match.pd > index 93dcef9..b3734f8 100644 > --- a/gcc/match.pd > +++ b/gcc/match.pd > @@ -831,6 +831,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > (bit_xor:c (bit_and:cs @0 (bit_not @1)) (bit_not @0)) > (bit_not (bit_and @0 @1))) > > +/* (~a & b) ^ a --> (a | b) */ > +(simplify > + (bit_xor:c (bit_and:cs (bit_not @0) @1) @0) > + (bit_ior @0 @1)) > + Are you sure? (~1804289383 & 846930886) ^ 1804289383 != 1804289383 | 846930886 #include <stdio.h> #include <stdlib.h> int main () { while (1) { int a = random(); int b = random(); if ((~a & b) ^ a != a | b) { fprintf (stderr, "%d, %d\n", a, b); abort (); } } } > /* (a | b) & ~(a ^ b) --> a & b */ > (simplify > (bit_and:c (bit_ior @0 @1) (bit_not (bit_xor:c @0 @1))) > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr91504.c > b/gcc/testsuite/gcc.dg/tree-ssa/pr91504.c > new file mode 100644 > index 0000000..a52dea4 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr91504.c > @@ -0,0 +1,18 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O -fdump-tree-optimized-raw" } */ > + > +static inline unsigned deposit32(unsigned value, int start, int length, > + unsigned fieldval) > +{ > + unsigned mask = (~0U >> (32 - length)) << start; > + return (value & ~mask) | ((fieldval << start) & mask); > +} > + > +unsigned foo(unsigned value) > +{ > + return deposit32(value, 10, 1, 1); > +} > + > +/* { dg-final { scan-tree-dump-not "bit_and_expr" "optimized" } } */ > +/* { dg-final { scan-tree-dump-not "bit_xor_expr" "optimized" } } */ > +/* { dg-final { scan-tree-dump-not "bit_not_expr" "optimized" } } */ >
On Mon, Aug 26, 2019 at 02:04:25PM +0200, Richard Biener wrote: > On Mon, 26 Aug 2019, kamlesh kumar wrote: > > +/* (~a & b) ^ a --> (a | b) */ > > +(simplify > > + (bit_xor:c (bit_and:cs (bit_not @0) @1) @0) > > + (bit_ior @0 @1)) > > + > > Are you sure? > > (~1804289383 & 846930886) ^ 1804289383 != 1804289383 | 846930886 Both are hex 7bfb67e7. a|b = a|(b&~a) = a^(b&~a) > if ((~a & b) ^ a != a | b) != has higher precedence than ^ and | (and &). Segher
On Mon, 26 Aug 2019, Segher Boessenkool wrote: > On Mon, Aug 26, 2019 at 02:04:25PM +0200, Richard Biener wrote: > > On Mon, 26 Aug 2019, kamlesh kumar wrote: > > > +/* (~a & b) ^ a --> (a | b) */ > > > +(simplify > > > + (bit_xor:c (bit_and:cs (bit_not @0) @1) @0) > > > + (bit_ior @0 @1)) > > > + > > > > Are you sure? > > > > (~1804289383 & 846930886) ^ 1804289383 != 1804289383 | 846930886 > > Both are hex 7bfb67e7. > > a|b = a|(b&~a) = a^(b&~a) > > > if ((~a & b) ^ a != a | b) > > != has higher precedence than ^ and | (and &). Oops. Need more coffee (and -Wall). Patch is OK. Thanks, Richard.
On 8/26/19 1:06 AM, kamlesh kumar wrote: > 2019-08-26 Kamlesh Kumar <kamleshbhalui@gmail.com> > > * gcc/match.pd: Added simplification > pattern. > * gcc.dg/tree-ssa/pr91504.c: New test. Thanks. I've installed this on the trunk. jeff
diff --git a/gcc/match.pd b/gcc/match.pd index 93dcef9..b3734f8 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -831,6 +831,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (bit_xor:c (bit_and:cs @0 (bit_not @1)) (bit_not @0)) (bit_not (bit_and @0 @1))) +/* (~a & b) ^ a --> (a | b) */ +(simplify + (bit_xor:c (bit_and:cs (bit_not @0) @1) @0) + (bit_ior @0 @1)) + /* (a | b) & ~(a ^ b) --> a & b */ (simplify (bit_and:c (bit_ior @0 @1) (bit_not (bit_xor:c @0 @1))) diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr91504.c b/gcc/testsuite/gcc.dg/tree-ssa/pr91504.c new file mode 100644 index 0000000..a52dea4 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr91504.c @@ -0,0 +1,18 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-optimized-raw" } */ + +static inline unsigned deposit32(unsigned value, int start, int length, + unsigned fieldval) +{ + unsigned mask = (~0U >> (32 - length)) << start; + return (value & ~mask) | ((fieldval << start) & mask); +} + +unsigned foo(unsigned value) +{ + return deposit32(value, 10, 1, 1); +} + +/* { dg-final { scan-tree-dump-not "bit_and_expr" "optimized" } } */ +/* { dg-final { scan-tree-dump-not "bit_xor_expr" "optimized" } } */ +/* { dg-final { scan-tree-dump-not "bit_not_expr" "optimized" } } */
2019-08-26 Kamlesh Kumar <kamleshbhalui@gmail.com> * gcc/match.pd: Added simplification pattern. * gcc.dg/tree-ssa/pr91504.c: New test. ====================