[PATCH] Optimize (x * 8) | 5 and (x << 3) ^ 3 to use lea (PR target/48688)
Jakub Jelinek
jakub@redhat.com
Sat Jun 4 15:40:00 GMT 2011
On Sat, Jun 04, 2011 at 08:19:57AM -0700, H.J. Lu wrote:
> I don't think this pattern is correct. See:
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49281
Fixed thusly, committed as obvious:
2011-06-04 Jakub Jelinek <jakub@redhat.com>
PR target/49281
* config/i386/i386.md (*lea_general_4): Require INTVAL (operands[3])
to be strictly smaller than 1 << shiftcount.
* gcc.c-torture/execute/pr49281.c: New test.
--- gcc/config/i386/i386.md.jj 2011-06-01 10:20:02.000000000 +0200
+++ gcc/config/i386/i386.md 2011-06-04 17:21:02.000000000 +0200
@@ -6425,7 +6425,7 @@ (define_insn_and_split "*lea_general_4"
|| 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])))"
+ < ((unsigned HOST_WIDE_INT) 1 << INTVAL (operands[2])))"
"#"
"&& reload_completed"
[(const_int 0)]
--- gcc/testsuite/gcc.c-torture/execute/pr49281.c.jj 2011-06-04 17:29:39.000000000 +0200
+++ gcc/testsuite/gcc.c-torture/execute/pr49281.c 2011-06-04 17:32:05.000000000 +0200
@@ -0,0 +1,25 @@
+/* PR target/49281 */
+
+extern void abort (void);
+
+__attribute__((noinline, noclone)) int
+foo (int x)
+{
+ return (x << 2) | 4;
+}
+
+__attribute__((noinline, noclone)) int
+bar (int x)
+{
+ return (x << 2) | 3;
+}
+
+int
+main ()
+{
+ if (foo (43) != 172 || foo (1) != 4 || foo (2) != 12)
+ abort ();
+ if (bar (43) != 175 || bar (1) != 7 || bar (2) != 11)
+ abort ();
+ return 0;
+}
Jakub
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