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Add X != !X pattern

Message ID alpine.LSU.2.11.1508051555030.19642@zhemvz.fhfr.qr
State New
Headers show

Commit Message

Richard Biener Aug. 5, 2015, 1:56 p.m. UTC 
On Wed, 5 Aug 2015, Richard Biener wrote:

> On Wed, 5 Aug 2015, Richard Biener wrote:
> 
> > On Wed, 5 Aug 2015, James Greenhalgh wrote:
> > 
> > > On Wed, Aug 05, 2015 at 12:09:35PM +0100, Richard Biener wrote:
> > > > On Wed, 5 Aug 2015, Andrew Pinski wrote:
> > > > 
> > > > > On Wed, Aug 5, 2015 at 3:16 AM, Richard Biener <rguenther@suse.de> wrote:
> > > > > > On Wed, 5 Aug 2015, Andreas Schwab wrote:
> > > > > >
> > > > > >> Richard Biener <rguenther@suse.de> writes:
> > > > > >>
> > > > > >> >     * gimple-fold.c (gimple_fold_stmt_to_constant_1): Canonicalize
> > > > > >> >     bool compares on RHS.
> > > > > >> >     * match.pd: Add X ==/!= !X is false/true pattern.
> > > > > >>
> > > > > >> ERROR in VTST/VTSTQ (/opt/gcc/gcc-20150805/gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/vtst.c line 97 in buffer 'expected_signed') at type uint8x8 index 1: got 0x1 != 0xff  (signed input)
> > > > > >> FAIL: gcc.target/aarch64/advsimd-intrinsics/vtst.c   -O1  execution test
> > > > > >> FAIL: gcc.target/aarch64/simd/int_comparisons_1.c scan-assembler-times [ \t]cmtst[ \t]+v[0-9]+.[0-9]+[bshd],[ \t]*v[0-9]+.[0-9]+[bshd],[ \t]+v[0-9]+.[0-9]+[bshd] 14
> > > > > >> FAIL: gcc.target/aarch64/simd/int_comparisons_1.c scan-assembler-times [ \t]cmtst[ \t]+d[0-9]+,[ \t]*d[0-9]+,[ \t]+d[0-9]+ 4
> > > > > >> FAIL: gcc.target/aarch64/simd/int_comparisons_2.c execution test
> > > > > >> FAIL: gcc.target/aarch64/singleton_intrinsics_1.c scan-assembler-times \\tcmtst\\td[0-9]+, d[0-9]+, d[0-9]+ 2
> > > > > >
> > > > > > Ick - somebody will have to come up with a reduced testcase for one of
> > > > > > this (best an execute fail).  Reduced to one failing case so I can
> > > > > > investigate with a cross compiler.
> > > > > >
> > > > > > Eventually smells like a aarch64 vector specific issue or a latent
> > > > > > issue with the truth_valued_p predicate for vector types.
> > > > > 
> > > > > Or constant_boolean_node is not returning {-1,-1,-1,-1} for true vectors.
> > > > 
> > > > It does.
> > > 
> > > You could try with the attached (execute) testcase.
> > > 
> > > Output for me (x86_64/AArch64 trunk compiler) is:
> > > 
> > >   Expected: 0000ffffffffff00 Got: 00007f80807f8000
> > > 
> > > Those folded values look suspicious! We fold as so:
> > > 
> > > arg1_2 = { -128, -1, 127, -122, -128, -1, 0, 118 };
> > > arg2_3 = { 127, -128, 127, -128, -1, 127, 127, 0 };
> > > 
> > > Visiting statement:
> > > _5 = arg1_2 & arg2_3;
> > > which is likely CONSTANT
> > > Match-and-simplified arg1_2 & arg2_3 to { 0, -128, 127, -128, -128, 127, 0, 0 }
> > > Lattice value changed to CONSTANT { 0, -128, 127, -128, -128, 127, 0, 0 }.  Adding SSA edges to worklist.
> > > interesting_ssa_edges: adding SSA use in _13 = VIEW_CONVERT_EXPR<uint8x8_t>(_5);
> > > marking stmt to be not simulated again
> > > 
> > > I'd have expected masks of "-1" in the true vector lanes rather than what
> > > we end up with.
> > 
> > __extension__ static __inline uint8x8_t __attribute__ 
> > ((__always_inline__))
> > vtst_s8 (int8x8_t __a, int8x8_t __b)
> > {
> >   return (uint8x8_t) ((__a & __b) != 0);
> > }
> > 
> > you expect that to be a truth and but it is a bitwise and.  So IMHO
> > it works "as expected".  Does the backend actually generate a truth-and
> > instruction for vtst_s8!?
> > 
> > Anyway, trying a cross now.
> 
> Reproduces on x86_64 as well, fix in testing.

For reference see below (testing on aarch64 appreciated).

Bootstrap & regtest running on x86_64-unknown-linux-gnu.

Richard.

2015-08-05  Richard Biener  <rguenther@suse.de>

	* gimple-fold.c (gimple_fold_stmt_to_constant_1): Simplify
	bool comparison canonicalization and restrict to integers.

Comments

Andreas Schwab Aug. 5, 2015, 2:32 p.m. UTC | #1 
Richard Biener <rguenther@suse.de> writes:

> For reference see below (testing on aarch64 appreciated).
>
> Bootstrap & regtest running on x86_64-unknown-linux-gnu.
>
> Richard.
>
> 2015-08-05  Richard Biener  <rguenther@suse.de>
>
> 	* gimple-fold.c (gimple_fold_stmt_to_constant_1): Simplify
> 	bool comparison canonicalization and restrict to integers.

Fixes all regressions on aarch64.

Andreas.
James Greenhalgh Aug. 5, 2015, 2:34 p.m. UTC | #2 
On Wed, Aug 05, 2015 at 02:56:08PM +0100, Richard Biener wrote:
> For reference see below (testing on aarch64 appreciated).

Looks good to me on aarch64-none-elf.

Thanks,
James

> Bootstrap & regtest running on x86_64-unknown-linux-gnu.
> 
> Richard.
> 
> 2015-08-05  Richard Biener  <rguenther@suse.de>
> 
> 	* gimple-fold.c (gimple_fold_stmt_to_constant_1): Simplify
> 	bool comparison canonicalization and restrict to integers.
diff mbox

Patch

Index: gcc/gimple-fold.c
===================================================================
--- gcc/gimple-fold.c	(revision 226612)
+++ gcc/gimple-fold.c	(working copy)
@@ -5041,20 +5095,12 @@  gimple_fold_stmt_to_constant_1 (gimple s
 		  {
 		    tree op1 = (*valueize) (gimple_assign_rhs2 (stmt));
 		    op0 = (*valueize) (op0);
-		    if (subcode == NE_EXPR)
-		      {
-			if (integer_zerop (op1))
-			  return op0;
-			else if (integer_zerop (op0))
-			  return op1;
-		      }
-		    else
-		      {
-			if (integer_onep (op1))
-			  return op0;
-			else if (integer_onep (op0))
-			  return op1;
-		      }
+		    if (TREE_CODE (op0) == INTEGER_CST)
+		      std::swap (op0, op1);
+		    if (TREE_CODE (op1) == INTEGER_CST
+			&& ((subcode == NE_EXPR && integer_zerop (op1))
+			    || (subcode == EQ_EXPR && integer_onep (op1))))
+		      return op0;
 		  }
 	      }
 	    return NULL_TREE;