Message ID | 000001cff73e$b36f90e0$1a4eb2a0$@arm.com |
---|---|
State | New |
Headers | show |
On 03/11/14 08:18, Zhenqiang Chen wrote: > Hi, > > pr45701-1.c FAIL for all tests. The patch updates it to check lr other than > r3, based on the comments in arm_compute_save_reg_mask, > > /* ... > Otherwise if we do not use the link register we do not need to save > it. If we are pushing other registers onto the stack however, we > can save an instruction in the epilogue by pushing the link register > now and then popping it back into the PC. This incurs extra memory > accesses though, so we only do it when optimizing for size, and only > if we know that we will not need a fancy return sequence. */ > > The updated case PASS for Cortex-M0/M4 and Cortext-A15 (THUMB and ARM > modes). > > OK for trunk? > > Thanks! > -Zhenqiang > > testsuite/ChangeLog: > 2014-11-03 Zhenqiang Chen <zhenqiang.chen@arm.com> > > * gcc.target/arm/pr45701-1.c: Check LR used. Have you checked that this doesn't cause regressions on ARMv4T? I suspect the code was originally intended to support targets where interworking was not trivial. R. > > diff --git a/gcc/testsuite/gcc.target/arm/pr45701-1.c > b/gcc/testsuite/gcc.target/arm/pr45701-1.c > index 2c690d5..c087cfc 100644 > --- a/gcc/testsuite/gcc.target/arm/pr45701-1.c > +++ b/gcc/testsuite/gcc.target/arm/pr45701-1.c > @@ -1,7 +1,7 @@ > /* { dg-do compile } */ > /* { dg-skip-if "" { ! { arm_thumb1_ok || arm_thumb2_ok } } } */ > /* { dg-options "-mthumb -Os" } */ > -/* { dg-final { scan-assembler "push\t\{r3" } } */ > +/* { dg-final { scan-assembler "lr\}" } } */ > /* { dg-final { scan-assembler-not "r8" } } */ > > extern int hist_verify; > > > > > >
> -----Original Message----- > From: Richard Earnshaw > Sent: Friday, November 07, 2014 8:51 PM > To: Zhenqiang Chen; gcc-patches@gcc.gnu.org > Cc: Ramana Radhakrishnan > Subject: Re: [PATCH, testsuite, ARM] Check lr other than r3 > > On 03/11/14 08:18, Zhenqiang Chen wrote: > > Hi, > > > > pr45701-1.c FAIL for all tests. The patch updates it to check lr other > > than r3, based on the comments in arm_compute_save_reg_mask, > > > > /* ... > > Otherwise if we do not use the link register we do not need to save > > it. If we are pushing other registers onto the stack however, we > > can save an instruction in the epilogue by pushing the link register > > now and then popping it back into the PC. This incurs extra memory > > accesses though, so we only do it when optimizing for size, and only > > if we know that we will not need a fancy return sequence. */ > > > > The updated case PASS for Cortex-M0/M4 and Cortext-A15 (THUMB and > ARM > > modes). > > > > OK for trunk? > > > > Thanks! > > -Zhenqiang > > > > testsuite/ChangeLog: > > 2014-11-03 Zhenqiang Chen <zhenqiang.chen@arm.com> > > > > * gcc.target/arm/pr45701-1.c: Check LR used. > > Have you checked that this doesn't cause regressions on ARMv4T? I suspect > the code was originally intended to support targets where interworking was > not trivial. Thanks for the comments. ARMV4T also saves LR and can pass with the patch. In function, thumb1_compute_save_reg_mask, we have code: /* LR will also be pushed if any lo regs are pushed. */ if (mask & 0xff || thumb_force_lr_save ()) mask |= (1 << LR_REGNUM); > > > > diff --git a/gcc/testsuite/gcc.target/arm/pr45701-1.c > > b/gcc/testsuite/gcc.target/arm/pr45701-1.c > > index 2c690d5..c087cfc 100644 > > --- a/gcc/testsuite/gcc.target/arm/pr45701-1.c > > +++ b/gcc/testsuite/gcc.target/arm/pr45701-1.c > > @@ -1,7 +1,7 @@ > > /* { dg-do compile } */ > > /* { dg-skip-if "" { ! { arm_thumb1_ok || arm_thumb2_ok } } } */ > > /* { dg-options "-mthumb -Os" } */ > > -/* { dg-final { scan-assembler "push\t\{r3" } } */ > > +/* { dg-final { scan-assembler "lr\}" } } */ > > /* { dg-final { scan-assembler-not "r8" } } */ > > > > extern int hist_verify; > > > > > > > > > > > >
diff --git a/gcc/testsuite/gcc.target/arm/pr45701-1.c b/gcc/testsuite/gcc.target/arm/pr45701-1.c index 2c690d5..c087cfc 100644 --- a/gcc/testsuite/gcc.target/arm/pr45701-1.c +++ b/gcc/testsuite/gcc.target/arm/pr45701-1.c @@ -1,7 +1,7 @@ /* { dg-do compile } */ /* { dg-skip-if "" { ! { arm_thumb1_ok || arm_thumb2_ok } } } */ /* { dg-options "-mthumb -Os" } */ -/* { dg-final { scan-assembler "push\t\{r3" } } */ +/* { dg-final { scan-assembler "lr\}" } } */ /* { dg-final { scan-assembler-not "r8" } } */ extern int hist_verify;