[adding the list]
On Jun 8, 2017, Uros Bizjak <ubiz...@gmail.com> wrote:
> On Thu, Jun 8, 2017 at 9:22 PM, Alexandre Oliva <aol...@redhat.com> wrote:
>> I was playing with bootstrap STAGE2_C{,XX}FLAGS='-O0 -fcompare-debug' to
>> test some changes I'm working on, and -Werror in stage2 prevented
>> compilation of one of the insn-*.c files. That's because round<mode>2
>> doesn't have an operand 2. The generated code for round<mode>2_sfix
>> calls the corresponding gen_round<mode>2, and then something in there
>> attempts to access the uninitialized operand, which the stage1 GCC warns
>> about and errors out because of -Werror.
>>
>> I'll be glad to test and submit a patch for this, but I thought I'd ask
>> whether you'd prefer to leave this alone, to have it fixed it with a
>> minimal diff as below, or with a renumbering of all operands >=3 to >=2?
> These operands are already pretty weirdly numbered, so the below looks
> appropriate as well.
> The proposed patch is OK.
Thanks, I'm checking this in. Regstrapped on x86_64-linux-gnu.
[i386] renumber operands to avoid gap
i386's round<mode>2 had a gap at operand 2, and so gen_round<mode>2
attempted to read from the uninitialized operand. Building stage2
with -O0 errored out, though at higher optimization levels it compiled
successfully. Fixed by renumbering the last operand into the gap.
for gcc/ChangeLog
* config/i386/sse.md (round<mode>2): Renumber operand into gap.
---
gcc/config/i386/sse.md | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index 29a039d..68c4bbe 100644
--- a/gcc/config/i386/sse.md
+++ b/gcc/config/i386/sse.md
@@ -15644,7 +15644,7 @@
(match_dup 3)))
(set (match_operand:VF 0 "register_operand")
(unspec:VF
- [(match_dup 4) (match_dup 5)]
+ [(match_dup 4) (match_dup 2)]
UNSPEC_ROUND))]
"TARGET_ROUND && !flag_trapping_math"
{
@@ -15668,7 +15668,7 @@
emit_insn (gen_copysign<mode>3 (operands[3], vec_half, operands[1]));
operands[4] = gen_reg_rtx (<MODE>mode);
- operands[5] = GEN_INT (ROUND_TRUNC);
+ operands[2] = GEN_INT (ROUND_TRUNC);
})
(define_expand "round<mode>2_sfix"
--
Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/ FSF Latin America board member
Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer
