diff mbox

[gomp4,PR68977,Committed] Don't gimplify in ssa mode if seen_error in oacc_xform_loop

Message ID 56A60033.4020507@mentor.com
State New
Headers show

Commit Message

Tom de Vries Jan. 25, 2016, 11 a.m. UTC 
On 14/01/16 10:43, Richard Biener wrote:
> On Wed, Jan 13, 2016 at 9:04 PM, Tom de Vries <Tom_deVries@mentor.com> wrote:
>> Hi,
>>
>> At r231739, there was an ICE when checking code generated by
>> oacc_xform_loop, in case the source contained an error.
>>
>> Due to seen_error (), gimplification during oacc_xform_loop bailed out, and
>> an uninitialized var was introduced.  Because of gimplifying in ssa mode,
>> that caused an ICE.
>>
>> I can't reproduce this any longer, but I think the fix still makes sense.
>> The patch makes sure oacc_xform_loop gimplifies in non-ssa mode if
>> seen_error ().
>
> I don't think it makes "sense" in any way.  After seen_error () a following ICE
> will be "confused after earlier errors" in release mode and thus I think that's
> not an important problem to paper over with this kind of "hack".
>
> I'd rather avoid doing any of omp-low if seen_error ()?
>

The error triggered in oacc_device_lower, so there's nothing we can do 
before (in omp-low).

How about this fix, which replaces the oacc ifn calls with 
zero-assignments if seen_error ()?

Thanks,
- Tom
diff mbox

Patch

Ignore oacc ifn if seen_error in execute_oacc_device_lower

---
 gcc/omp-low.c | 39 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index 2de3aeb..f678f05 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -20201,7 +20201,7 @@  execute_oacc_device_lower ()
 
 	/* Rewind to allow rescan.  */
 	gsi_prev (&gsi);
-	bool rescan = false, remove = false;
+	bool rescan = false, remove = false, assign_zero = false;
 	enum  internal_fn ifn_code = gimple_call_internal_fn (call);
 
 	switch (ifn_code)
@@ -20209,11 +20209,25 @@  execute_oacc_device_lower ()
 	  default: break;
 
 	  case IFN_GOACC_LOOP:
+	    if (seen_error ())
+	      {
+		remove = true;
+		assign_zero = true;
+		break;
+	      }
+
 	    oacc_xform_loop (call);
 	    rescan = true;
 	    break;
 
 	  case IFN_GOACC_REDUCTION:
+	    if (seen_error ())
+	      {
+		remove = true;
+		assign_zero = true;
+		break;
+	      }
+
 	    /* Mark the function for SSA renaming.  */
 	    mark_virtual_operands_for_renaming (cfun);
 
@@ -20228,6 +20242,13 @@  execute_oacc_device_lower ()
 
 	  case IFN_UNIQUE:
 	    {
+	      if (seen_error ())
+		{
+		  remove = true;
+		  assign_zero = true;
+		  break;
+		}
+
 	      enum ifn_unique_kind kind
 		= ((enum ifn_unique_kind)
 		   TREE_INT_CST_LOW (gimple_call_arg (call, 0)));
@@ -20266,11 +20287,19 @@  execute_oacc_device_lower ()
 	  {
 	    if (gimple_vdef (call))
 	      replace_uses_by (gimple_vdef (call), gimple_vuse (call));
-	    if (gimple_call_lhs (call))
+	    tree lhs = gimple_call_lhs (call);
+	    if (lhs != NULL_TREE)
 	      {
-		/* Propagate the data dependency var.  */
-		gimple *ass = gimple_build_assign (gimple_call_lhs (call),
-						   gimple_call_arg (call, 1));
+		gimple *ass;
+		if (assign_zero)
+		  {
+		    tree zero = build_zero_cst (TREE_TYPE (lhs));
+		    ass = gimple_build_assign (lhs, zero);
+		  }
+		else
+		  /* Propagate the data dependency var.  */
+		  ass = gimple_build_assign (lhs, gimple_call_arg (call, 1));
+
 		gsi_replace (&gsi, ass,  false);
 	      }
 	    else