On Fri, Oct 14, 2011 at 9:23 AM, Paolo Bonzini <bonz...@gnu.org> wrote:
> On 10/14/2011 05:36 PM, H.J. Lu wrote:
>>
>> There is a testcase at
>>
>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50696
>>
>> It passes with my patch.
>
> Cool, so let's wait for the results of testing.
>
> Paolo
>
Here is the complete patch with a testcase. I will
check it in if there are no performance regressions
with SPEC CPU 2K/2006 on Linux/ia32/x86-64/x32.
Thanks.
--
H.J.
---
gcc/
2011-10-13 H.J. Lu <hongjiu...@intel.com>
PR rtl-optimization/50696
* combine.c (make_compound_operation): Turn (and (OP) M) into
extraction if M is an extraction mask.
gcc/testsuite/
2011-10-13 H.J. Lu <hongjiu...@intel.com>
PR rtl-optimization/50696
* gcc.target/i386/pr50696.c: New.
gcc/
2011-10-13 H.J. Lu <hongjiu...@intel.com>
PR rtl-optimization/50696
* combine.c (make_compound_operation): Turn (and (OP) M) into
extraction if M is an extraction mask.
gcc/testsuite/
2011-10-13 H.J. Lu <hongjiu...@intel.com>
PR rtl-optimization/50696
* gcc.target/i386/pr50696.c: New.
diff --git a/gcc/combine.c b/gcc/combine.c
index 6c3b17c..4b57b88 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -7739,16 +7739,6 @@ make_compound_operation (rtx x, enum rtx_code in_code)
XEXP (XEXP (x, 0), 1)));
}
- /* If the constant is one less than a power of two, this might be
- representable by an extraction even if no shift is present.
- If it doesn't end up being a ZERO_EXTEND, we will ignore it unless
- we are in a COMPARE. */
- else if ((i = exact_log2 (UINTVAL (XEXP (x, 1)) + 1)) >= 0)
- new_rtx = make_extraction (mode,
- make_compound_operation (XEXP (x, 0),
- next_code),
- 0, NULL_RTX, i, 1, 0, in_code == COMPARE);
-
/* If we are in a comparison and this is an AND with a power of two,
convert this into the appropriate bit extract. */
else if (in_code == COMPARE
@@ -7758,6 +7748,26 @@ make_compound_operation (rtx x, enum rtx_code in_code)
next_code),
i, NULL_RTX, 1, 1, 0, 1);
+ /* If the constant is an extraction mask with the zero bits in
+ the first operand ignored, this might be representable by an
+ extraction even if no shift is present. If it doesn't end up
+ being a ZERO_EXTEND, we will ignore it unless we are in a
+ COMPARE. */
+ else
+ {
+ unsigned HOST_WIDE_INT nonzero =
+ nonzero_bits (XEXP (x, 0), GET_MODE (XEXP (x, 0)));
+ unsigned HOST_WIDE_INT mask = UINTVAL (XEXP (x, 1));
+ unsigned HOST_WIDE_INT len = ceil_log2 (mask);
+ if ((nonzero & (((unsigned HOST_WIDE_INT) 1 << len) - 1))
+ == (nonzero & mask))
+ {
+ new_rtx = make_compound_operation (XEXP (x, 0), next_code);
+ new_rtx = make_extraction (mode, new_rtx, 0, NULL_RTX,
+ len, 1, 0, in_code == COMPARE);
+ }
+ }
+
break;
case LSHIFTRT:
diff --git a/gcc/testsuite/gcc.target/i386/pr50696.c b/gcc/testsuite/gcc.target/i386/pr50696.c
new file mode 100644
index 0000000..b1ec2c5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr50696.c
@@ -0,0 +1,19 @@
+/* { dg-do compile { target { x32 } } } */
+/* { dg-options "-O2 -mtune=generic" } */
+
+struct s { int val[16]; };
+
+extern void f (struct s pb);
+
+void
+foo ()
+{
+ struct s x;
+ int i;
+
+ for (i = 0; i < 16; i++)
+ x.val[i] = i + 1;
+ f (x);
+}
+
+/* { dg-final { scan-assembler-not "lea\[lq\]" } } */
