On 5/18/21 12:34 PM, Richard Biener wrote:
> On Tue, 18 May 2021, Xionghu Luo wrote:
>
>> Hi,
>>
>> On 2021/5/18 15:02, Richard Biener wrote:
>>> Can you, for the new gcc.dg/tree-ssa/ssa-sink-18.c testcase, add
>>> a comment explaining what operations we expect to sink? The testcase
>>> is likely somewhat fragile in the exact number of sinkings
>>> (can you check on some other target and maybe P8BE with -m32 for
>>> example?), so for future adjustments it would be nice to easiliy
>>> figure out what we expect to happen.
>>>
>>> OK with that change.
>>
>> Thanks a lot for the reminder! ssa-sink-18.c generates different code
>> for m32 and m64 exactly due to different type size conversion and ivopts
>> selection, since -m32 and -m64 couldn't co-exist in one test file, shall
>> I restrict it to -m64 only or check target lp64/target ilp32?
>> I've verified this case shows same behavior on X86, AArch64 and Power for
>> both m32 and m64.
>>
>> -m32:
>> <bb 29> [local count: 75120046]:
>> # len_155 = PHI <len_127(28), len_182(55)>
>> len_182 = len_155 + 1;
>> _35 = (unsigned int) ip_249;
>> _36 = _35 + len_182;
>> _380 = (uint8_t *) _36;
>> if (maxlen_179 > len_182)
>> goto <bb 30>; [94.50%]
>> else
>> goto <bb 31>; [5.50%]
>> ...
>>
>> Sinking _329 = (uint8_t *) _36;
>> from bb 29 to bb 86
>> Sinking _36 = _35 + len_182;
>> from bb 29 to bb 86
>> Sinking _35 = (unsigned int) ip_249;
>> from bb 29 to bb 86
>>
>> Pass statistics of "sink": ----------------
>> Sunk statements: 3
>>
>>
>> -m64:
>> <bb 29> [local count: 75120046]:
>> # ivtmp.23_34 = PHI <ivtmp.23_36(28), ivtmp.23_35(55)>
>> _38 = (unsigned int) ivtmp.23_34;
>> len_161 = _38 + 4294967295;
>> _434 = (unsigned long) ip_254;
>> _433 = ivtmp.23_34 + _434;
>> _438 = (uint8_t *) _433;
>> if (_38 < maxlen_187)
>> goto <bb 30>; [94.50%]
>> else
>> goto <bb 31>; [5.50%]
>> ...
>>
>> Sinking _367 = (uint8_t *) _320;
>> from bb 31 to bb 90
>> Sinking _320 = _321 + ivtmp.25_326;
>> from bb 31 to bb 90
>> Sinking _321 = (unsigned long) ip_229;
>> from bb 31 to bb 90
>> Sinking len_158 = _322 + 4294967295;
>> from bb 31 to bb 33
>>
>> Pass statistics of "sink": ----------------
>> Sunk statements: 4
>>
>>
>> Regarding to the comments part:
>>
>> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-18.c
>> b/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-18.c
>> index 52b9a74b65f..5147f7b85cd 100644
>> --- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-18.c
>> +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-18.c
>> @@ -193,16 +193,17 @@ compute_on_bytes (uint8_t *in_data, int in_len,
>> uint8_t *out_data, int out_len)
>> return op - out_data;
>> }
>> + /* For this case, pass sink2 sinks statements from hot loop header to loop
>> + exits after gimple loop optimizations, which generates instructions
>> executed
>> + each iteration in loop, but the results are used outside of loop:
>> + With -m64,
>> + "Sinking _367 = (uint8_t *) _320;
>> + from bb 31 to bb 90
>> + Sinking _320 = _321 + ivtmp.25_326;
>> + from bb 31 to bb 90
>> + Sinking _321 = (unsigned long) ip_229;
>> + from bb 31 to bb 90
>> + Sinking len_158 = _322 + 4294967295;
>> + from bb 31 to bb 33" */
>>
>> - /* { dg-final { scan-tree-dump-times "Sunk statements: 4" 1 "sink2" } } */
>> + /* { dg-final { scan-tree-dump-times "Sunk statements: 4" 1 "sink2" {
>> target lp64 } } } */
>> + /* { dg-final { scan-tree-dump-times "Sunk statements: 3" 1 "sink2" {
>> target ilp32 } } } */
>
> Yes, that looks good.
>
> Thanks,
> Richard.
>
Hi,
I've noticed the test case gcc.dg/tree-ssa/ssa-sink-3.c was accidentally
committed as empty file, and therefore fails:
FAIL: gcc.dg/tree-ssa/ssa-sink-3.c (test for excess errors)
I've commited as obvious the following fix (which restores the test case and
Xionghu Luo's intended change.
Thanks
Bernd.
From 51cfa55431c38f3c29c7b72833337ad8a2da5c06 Mon Sep 17 00:00:00 2001
From: Bernd Edlinger <[email protected]>
Date: Wed, 19 May 2021 09:51:44 +0200
Subject: [PATCH] Fix commit mistake in testcase gcc.dg/tree-ssa/ssa-sink-3.c
the test case was accidenally changed to empty file.
2021-05-19 Bernd Edlinger <[email protected]>
* gcc.dg/tree-ssa/ssa-sink-3.c: Fix test case.
---
gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-3.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-3.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-3.c
index e69de29..ad88ccc 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-3.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-3.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-sink-stats" } */
+extern void foo(int a);
+int
+main (int argc)
+{
+ int a;
+ a = argc + 1;
+ if (argc + 3)
+ {
+ foo (a);
+ }
+}
+/* We should sink the a = argc + 1 calculation into the if branch */
+/* { dg-final { scan-tree-dump-times "Sunk statements: 1" 1 "sink1" } } */
--
1.9.1
