On January 16, 2021 1:59:50 AM GMT+01:00, Jakub Jelinek <ja...@redhat.com> wrote: >On Fri, Jan 15, 2021 at 09:21:07PM +0100, Richard Biener wrote: >> >BTW, I've tried to also fix what the PR wanted primarily by adding >> >/* Simplify (CST << x) & 1 to 0 if CST is even or to x == 0 if it is >> >odd. / >> >(simplify >> > (bit_and (lshift INTEGER_CST@1 @0) integer_onep) >> > (if ((wi::to_wide (@1) & 1) != 0) >> > (eq @0 { build_zero_cst (TREE_TYPE (@0)); }) >> > ({ build_zero_cst (type); }))) >> >simplifier before this one, but genmatch.c doesn't seem to put it >into >> >the >> >resulting files. Is there a way to figure out what is going on? > >Actually, it was a PEBKAC, it helps when the comment termination is */ >rather than just / alone. > >The following works fine, no need to stick it into an unrelated >pattern. > >Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok. Richard. >2021-01-15 Jakub Jelinek <ja...@redhat.com> > > PR tree-optimization/96669 > * match.pd ((CST << x) & 1 -> x == 0): New simplification. > > * gcc.dg/tree-ssa/pr96669-1.c: Adjust regexp. > * gcc.dg/tree-ssa/pr96669-2.c: New test. > >--- gcc/match.pd.jj 2021-01-15 21:12:07.656060308 +0100 >+++ gcc/match.pd 2021-01-15 23:51:34.038119715 +0100 >@@ -3117,6 +3117,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > (op @0 { build_int_cst (TREE_TYPE (@1), low); }))))))) > > >+/* Simplify (CST << x) & 1 to 0 if CST is even or to x == 0 if it is >odd. */ >+(simplify >+ (bit_and (lshift INTEGER_CST@1 @0) integer_onep) >+ (if ((wi::to_wide (@1) & 1) != 0) >+ (convert (eq:boolean_type_node @0 { build_zero_cst (TREE_TYPE >(@0)); })) >+ { build_zero_cst (type); })) >+ >/* Simplify ((C << x) & D) != 0 where C and D are power of two >constants, > either to false if D is smaller (unsigned comparison) than C, or to > x == log2 (D) - log2 (C). Similarly for right shifts. */ >--- gcc/testsuite/gcc.dg/tree-ssa/pr96669-1.c.jj 2021-01-15 >22:03:18.089279035 +0100 >+++ gcc/testsuite/gcc.dg/tree-ssa/pr96669-1.c 2021-01-16 >01:55:42.800379400 +0100 >@@ -1,7 +1,7 @@ > /* PR tree-optimization/96669 */ > /* { dg-do compile } */ > /* { dg-options "-O2 -fdump-tree-original" } */ >-/* { dg-final { scan-tree-dump "return a == 0;" "original" } } */ >+/* { dg-final { scan-tree-dump "a == 0" "original" } } */ > /* { dg-final { scan-tree-dump "return 1;" "original" } } */ > /* { dg-final { scan-tree-dump "return c == 3;" "original" } } */ > /* { dg-final { scan-tree-dump "return d != 1;" "original" } } */ >--- gcc/testsuite/gcc.dg/tree-ssa/pr96669-2.c.jj 2021-01-15 >22:03:47.075951818 +0100 >+++ gcc/testsuite/gcc.dg/tree-ssa/pr96669-2.c 2021-01-16 >01:56:02.859156051 +0100 >@@ -0,0 +1,30 @@ >+/* PR tree-optimization/96669 */ >+/* { dg-do compile } */ >+/* { dg-options "-O2 -fdump-tree-original" } */ >+/* { dg-final { scan-tree-dump "a == 0" "original" } } */ >+/* { dg-final { scan-tree-dump-times "return 0;" 2 "original" } } */ >+/* { dg-final { scan-tree-dump "c == 0" "original" } } */ >+ >+int >+f1 (int a) >+{ >+ return ((1 << a) & 1); >+} >+ >+int >+f2 (int b) >+{ >+ return ((2 << b) & 1); >+} >+ >+int >+f3 (int c) >+{ >+ return ((35 << c) & 1); >+} >+ >+int >+f4 (int d) >+{ >+ return ((42 << d) & 1); >+} > > > Jakub