| Message ID | 20180621123342.fqyitbmaxpkcayih@localhost.localdomain |
|---|---|
| State | New |
| Headers | show |
| Series | [testsuite] Fix guality/pr45882.c for flto | expand |
On Thu, 21 Jun 2018, Tom de Vries wrote: > Hi, > > Atm this test in pr45882.c: > ... > int d = a[i]; /* { dg-final { gdb-test 16 "d" "112" } } */ > ... > fails as follows with -flto: > ... > FAIL: gcc.dg/guality/pr45882.c -O2 -flto -fuse-linker-plugin \ > -fno-fat-lto-objects line 16 d == 112 > ... > > In more detail, gdb fails to print the value of d: > ... > Breakpoint 1, foo (i=i@entry=7, j=j@entry=7) at pr45882.c:16 > 16 ++v; > $1 = <optimized out> > $2 = 112 > <optimized out> != 112 > ... > > Variable d is a local variable in function foo, initialized from global array a. > When compiling, first cddce1 removes the initialization of d in foo, given > that d is not used afterwards. Then ipa marks array a as write-only, and > removes the stores to array a in main. This invalidates the location > expression for d, which points to a[i], so it is removed, which is why gdb > ends up printing <optimized out> for d. > > This patches fixes the fail by adding attribute used to array a, preventing > array a from being marked as write-only. > > Tested on x86_64. > > OK for trunk? OK. Richard. > Thanks, > - Tom > > [testsuite] Fix guality/pr45882.c for flto > > 2018-06-21 Tom de Vries <tdevries@suse.de> > > * gcc.dg/guality/pr45882.c (a): Add used attribute. > > --- > gcc/testsuite/gcc.dg/guality/pr45882.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/gcc/testsuite/gcc.dg/guality/pr45882.c b/gcc/testsuite/gcc.dg/guality/pr45882.c > index 5ca22d4f4ad..ece35238a30 100644 > --- a/gcc/testsuite/gcc.dg/guality/pr45882.c > +++ b/gcc/testsuite/gcc.dg/guality/pr45882.c > @@ -3,7 +3,7 @@ > /* { dg-options "-g" } */ > > extern void abort (void); > -int a[1024]; > +int a[1024] __attribute__((used)); > volatile short int v; > > __attribute__((noinline,noclone,used)) int > >
diff --git a/gcc/testsuite/gcc.dg/guality/pr45882.c b/gcc/testsuite/gcc.dg/guality/pr45882.c index 5ca22d4f4ad..ece35238a30 100644 --- a/gcc/testsuite/gcc.dg/guality/pr45882.c +++ b/gcc/testsuite/gcc.dg/guality/pr45882.c @@ -3,7 +3,7 @@ /* { dg-options "-g" } */ extern void abort (void); -int a[1024]; +int a[1024] __attribute__((used)); volatile short int v; __attribute__((noinline,noclone,used)) int
Hi, Atm this test in pr45882.c: ... int d = a[i]; /* { dg-final { gdb-test 16 "d" "112" } } */ ... fails as follows with -flto: ... FAIL: gcc.dg/guality/pr45882.c -O2 -flto -fuse-linker-plugin \ -fno-fat-lto-objects line 16 d == 112 ... In more detail, gdb fails to print the value of d: ... Breakpoint 1, foo (i=i@entry=7, j=j@entry=7) at pr45882.c:16 16 ++v; $1 = <optimized out> $2 = 112 <optimized out> != 112 ... Variable d is a local variable in function foo, initialized from global array a. When compiling, first cddce1 removes the initialization of d in foo, given that d is not used afterwards. Then ipa marks array a as write-only, and removes the stores to array a in main. This invalidates the location expression for d, which points to a[i], so it is removed, which is why gdb ends up printing <optimized out> for d. This patches fixes the fail by adding attribute used to array a, preventing array a from being marked as write-only. Tested on x86_64. OK for trunk? Thanks, - Tom [testsuite] Fix guality/pr45882.c for flto 2018-06-21 Tom de Vries <tdevries@suse.de> * gcc.dg/guality/pr45882.c (a): Add used attribute. --- gcc/testsuite/gcc.dg/guality/pr45882.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)