On Mon, Jan 20, 2014 at 1:11 AM, Uros Bizjak <ubiz...@gmail.com> wrote:
> On Mon, Jan 20, 2014 at 9:38 AM, Jakub Jelinek <ja...@redhat.com> wrote:
>
>> As mentioned in the PR or even in the comment below, ix86_decompose_address
>> sometimes sets parts.base to some REG and parts.disp to const0_rtx, even
>> when the operands aren't of a lea insn, but normal or zero extending mov.
>>
>> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
>> trunk?
>>
>> 2014-01-20 Jakub Jelinek <ja...@redhat.com>
>>
>> PR target/59880
>> * config/i386/i386.c (ix86_avoid_lea_for_addr): Return false
>> if operands[1] is a REG or ZERO_EXTEND of a REG.
>>
>> * gcc.target/i386/pr59880.c: New test.
>
>> --- gcc/config/i386/i386.c.jj 2014-01-19 12:18:49.000000000 +0100
>> +++ gcc/config/i386/i386.c 2014-01-19 19:02:34.078168289 +0100
>> @@ -18159,8 +18159,19 @@ ix86_avoid_lea_for_addr (rtx insn, rtx o
>> if (!TARGET_AVOID_LEA_FOR_ADDR || optimize_function_for_size_p (cfun))
>> return false;
>>
>> + /* The "at least two components" test below might not catch simple
>> + *mov[sd]i_internal or *zero_extendsidi2 insns if parts.base is
>> + non-NULL and parts.disp is const0_rtx as the only components in
>> + the address, e.g. if the register is %rbp or %r13. As this
>> + test is much cheaper and moves or zero extensions are the common
>> + case, do this check first. */
>> + if (REG_P (operands[1])
>> + || (GET_CODE (operands[1]) == ZERO_EXTEND
>> + && REG_P (XEXP (operands[1], 0))))
>> + return false;
>> +
>> /* Check it is correct to split here. */
>> - if (!ix86_ok_to_clobber_flags(insn))
>> + if (!ix86_ok_to_clobber_flags (insn))
>> return false;
>>
>> ok = ix86_decompose_address (operands[1], &parts);
>> --- gcc/testsuite/gcc.target/i386/pr59880.c.jj 2014-01-19
>> 19:24:44.094382629 +0100
>> +++ gcc/testsuite/gcc.target/i386/pr59880.c 2014-01-19
>> 19:25:30.000000000 +0100
>> @@ -0,0 +1,14 @@
>> +/* PR target/59880 */
>> +/* { dg-do compile { target { ! ia32 } } } */
>> +/* { dg-options "-O2 -mtune=silvermont" } */
>> +
>> +register unsigned int r13 __asm ("r13");
>> +unsigned long long
>> +foo (void)
>> +{
>> + return r13;
>> +}
>> +
>> +/* Ensure we don't emit a useless zero-extension after another
>> + zero-extension. */
>> +/* { dg-final { scan-assembler-not "%eax, %eax" } } */
>>
>> Jakub
>
> This is OK for mainline, I will take care for a backport (together
> with 59379) to other release branches.
>
I backported gcc.target/i386/pr59880.c to 4.8 branch by
replacing -mtune=silvermont with -mtune=slm.
Thanks.
--
H.J.
--
Index: ChangeLog
===================================================================
--- ChangeLog (revision 206941)
+++ ChangeLog (working copy)
@@ -1,3 +1,11 @@
+2014-01-22 H.J. Lu <hongjiu...@intel.com>
+
+ Backport from mainline
+ 2014-01-20 Jakub Jelinek <ja...@redhat.com>
+
+ PR target/59880
+ * gcc.target/i386/pr59880.c: New test.
+
2014-01-21 Jakub Jelinek <ja...@redhat.com>
PR middle-end/59860
Index: gcc.target/i386/pr59880.c
===================================================================
--- gcc.target/i386/pr59880.c (revision 0)
+++ gcc.target/i386/pr59880.c (working copy)
@@ -0,0 +1,14 @@
+/* PR target/59880 */
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-O2 -mtune=slm" } */
+
+register unsigned int r13 __asm ("r13");
+unsigned long long
+foo (void)
+{
+ return r13;
+}
+
+/* Ensure we don't emit a useless zero-extension after another
+ zero-extension. */
+/* { dg-final { scan-assembler-not "%eax, %eax" } } */
