Re: [PATCH] Optimize (x * 8) | 5 and (x 3) ^ 3 to use lea (PR target/48688)
On Wed, Apr 20, 2011 at 9:09 AM, Jakub Jelinek ja...@redhat.com wrote:
Hi!
This splitter allows us to optimize (x {* {2,4,8}, {1,2,3}}) {|,^} y
for constant integer y = {1ULL,3ULL,7ULL} using lea{l,q} (| or ^ in
that case, when the low bits are known to be all 0, is like plus).
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2011-04-20 Jakub Jelinek ja...@redhat.com
PR target/48688
* config/i386/i386.md (*lea_general_4): New define_insn_and_split.
* gcc.target/i386/pr48688.c: New test.
--- gcc/config/i386/i386.md.jj 2011-04-19 14:08:55.0 +0200
+++ gcc/config/i386/i386.md 2011-04-20 14:34:50.0 +0200
@@ -6646,6 +6646,40 @@ (define_insn_and_split *lea_general_3_z
}
[(set_attr type lea)
(set_attr mode SI)])
+
+(define_insn_and_split *lea_general_4
+ [(set (match_operand:SWI 0 register_operand =r)
+ (any_or:SWI (ashift:SWI (match_operand:SWI 1 index_register_operand
l)
+ (match_operand:SWI 2 const_int_operand n))
+ (match_operand 3 const_int_operand n)))]
+ (MODEmode == DImode
+ || MODEmode == SImode
+ || !TARGET_PARTIAL_REG_STALL
+ || optimize_function_for_size_p (cfun))
+ ((unsigned HOST_WIDE_INT) INTVAL (operands[2])) - 1 3
+ ((unsigned HOST_WIDE_INT) INTVAL (operands[3])
+ = ((unsigned HOST_WIDE_INT) 1 INTVAL (operands[2])))
+ #
+ reload_completed
+ [(const_int 0)]
+{
+ rtx pat;
+ if (MODEmode != DImode)
+ operands[0] = gen_lowpart (SImode, operands[0]);
+ operands[1] = gen_lowpart (Pmode, operands[1]);
+ operands[2] = GEN_INT (1 INTVAL (operands[2]));
+ pat = plus_constant (gen_rtx_MULT (Pmode, operands[1], operands[2]),
+ INTVAL (operands[3]));
+ if (Pmode != SImode MODEmode != DImode)
+ pat = gen_rtx_SUBREG (SImode, pat, 0);
+ emit_insn (gen_rtx_SET (VOIDmode, operands[0], pat));
+ DONE;
+}
+ [(set_attr type lea)
+ (set (attr mode)
+ (if_then_else (eq (symbol_ref MODEmode == DImode) (const_int 0))
+ (const_string SI)
+ (const_string DI)))])
;; Subtract instructions
I don't think this pattern is correct. See:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49281
H.J.
Re: [PATCH] Optimize (x * 8) | 5 and (x 3) ^ 3 to use lea (PR target/48688)
On Wed, Apr 20, 2011 at 10:27:36AM -0700, Richard Henderson wrote:
On 04/20/2011 09:09 AM, Jakub Jelinek wrote:
Hi!
This splitter allows us to optimize (x {* {2,4,8}, {1,2,3}}) {|,^} y
for constant integer y = {1ULL,3ULL,7ULL} using lea{l,q} (| or ^ in
that case, when the low bits are known to be all 0, is like plus).
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2011-04-20 Jakub Jelinek ja...@redhat.com
PR target/48688
* config/i386/i386.md (*lea_general_4): New define_insn_and_split.
Any chance you could do this in combine instead? Shift-and-add patterns
are a fairly common architectural feature...
I've tried to do it in simplify-rtx.c, unfortunately combine.c does exactly
opposite canonicalization and thus it results in endless recursion:
/* If we are adding two things that have no bits in common, convert
the addition into an IOR. This will often be further simplified,
for example in cases like ((a 1) + (a 2)), which can
become a 3. */
if (GET_MODE_BITSIZE (mode) = HOST_BITS_PER_WIDE_INT
(nonzero_bits (XEXP (x, 0), mode)
nonzero_bits (XEXP (x, 1), mode)) == 0)
{
/* Try to simplify the expression further. */
rtx tor = simplify_gen_binary (IOR, mode, XEXP (x, 0), XEXP (x, 1));
temp = combine_simplify_rtx (tor, mode, in_dest, 0);
/* If we could, great. If not, do not go ahead with the IOR
replacement, since PLUS appears in many special purpose
address arithmetic instructions. */
if (GET_CODE (temp) != CLOBBER temp != tor)
return temp;
}
So at least it can't be done in simplify_binary_operation_1.
Jakub
[PATCH] Optimize (x * 8) | 5 and (x 3) ^ 3 to use lea (PR target/48688)
Hi!
This splitter allows us to optimize (x {* {2,4,8}, {1,2,3}}) {|,^} y
for constant integer y = {1ULL,3ULL,7ULL} using lea{l,q} (| or ^ in
that case, when the low bits are known to be all 0, is like plus).
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2011-04-20 Jakub Jelinek ja...@redhat.com
PR target/48688
* config/i386/i386.md (*lea_general_4): New define_insn_and_split.
* gcc.target/i386/pr48688.c: New test.
--- gcc/config/i386/i386.md.jj 2011-04-19 14:08:55.0 +0200
+++ gcc/config/i386/i386.md 2011-04-20 14:34:50.0 +0200
@@ -6646,6 +6646,40 @@ (define_insn_and_split *lea_general_3_z
}
[(set_attr type lea)
(set_attr mode SI)])
+
+(define_insn_and_split *lea_general_4
+ [(set (match_operand:SWI 0 register_operand =r)
+ (any_or:SWI (ashift:SWI (match_operand:SWI 1 index_register_operand
l)
+ (match_operand:SWI 2 const_int_operand n))
+ (match_operand 3 const_int_operand n)))]
+ (MODEmode == DImode
+|| MODEmode == SImode
+|| !TARGET_PARTIAL_REG_STALL
+|| optimize_function_for_size_p (cfun))
+((unsigned HOST_WIDE_INT) INTVAL (operands[2])) - 1 3
+((unsigned HOST_WIDE_INT) INTVAL (operands[3])
+ = ((unsigned HOST_WIDE_INT) 1 INTVAL (operands[2])))
+ #
+ reload_completed
+ [(const_int 0)]
+{
+ rtx pat;
+ if (MODEmode != DImode)
+operands[0] = gen_lowpart (SImode, operands[0]);
+ operands[1] = gen_lowpart (Pmode, operands[1]);
+ operands[2] = GEN_INT (1 INTVAL (operands[2]));
+ pat = plus_constant (gen_rtx_MULT (Pmode, operands[1], operands[2]),
+ INTVAL (operands[3]));
+ if (Pmode != SImode MODEmode != DImode)
+pat = gen_rtx_SUBREG (SImode, pat, 0);
+ emit_insn (gen_rtx_SET (VOIDmode, operands[0], pat));
+ DONE;
+}
+ [(set_attr type lea)
+ (set (attr mode)
+ (if_then_else (eq (symbol_ref MODEmode == DImode) (const_int 0))
+ (const_string SI)
+ (const_string DI)))])
;; Subtract instructions
--- gcc/testsuite/gcc.target/i386/pr48688.c.jj 2011-04-20 14:55:37.0
+0200
+++ gcc/testsuite/gcc.target/i386/pr48688.c 2011-04-20 14:57:03.0
+0200
@@ -0,0 +1,24 @@
+/* PR target/48688 */
+/* { dg-do compile } */
+/* { dg-options -O2 } */
+
+int fn1 (int x) { return (x 3) | 5; }
+int fn2 (int x) { return (x * 8) | 5; }
+int fn3 (int x) { return (x 3) + 5; }
+int fn4 (int x) { return (x * 8) + 5; }
+int fn5 (int x) { return (x 3) ^ 5; }
+int fn6 (int x) { return (x * 8) ^ 5; }
+long fn7 (long x) { return (x 3) | 5; }
+long fn8 (long x) { return (x * 8) | 5; }
+long fn9 (long x) { return (x 3) + 5; }
+long fn10 (long x) { return (x * 8) + 5; }
+long fn11 (long x) { return (x 3) ^ 5; }
+long fn12 (long x) { return (x * 8) ^ 5; }
+long fn13 (unsigned x) { return (x 3) | 5; }
+long fn14 (unsigned x) { return (x * 8) | 5; }
+long fn15 (unsigned x) { return (x 3) + 5; }
+long fn16 (unsigned x) { return (x * 8) + 5; }
+long fn17 (unsigned x) { return (x 3) ^ 5; }
+long fn18 (unsigned x) { return (x * 8) ^ 5; }
+
+/* { dg-final { scan-assembler-not \[ \t\]x?or\[bwlq\]\[ \t\] } } */
Jakub
