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 14:08:55.000000000 +0200
+++ gcc/config/i386/i386.md 2011-04-20 14:34:50.000000000 +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")))]
+ "(<MODE>mode == DImode
+ || <MODE>mode == 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 (<MODE>mode != 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 && <MODE>mode != 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 "<MODE>mode == DImode") (const_int 0))
+ (const_string "SI")
+ (const_string "DI")))])
;; Subtract instructions
--- gcc/testsuite/gcc.target/i386/pr48688.c.jj 2011-04-20 14:55:37.000000000
+0200
+++ gcc/testsuite/gcc.target/i386/pr48688.c 2011-04-20 14:57:03.000000000
+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
