Don't pass vector params through to offload targets

The optimization options are deliberately passed through to the LTO compiler,
but when the same mechanism is reused for offloading it ends up forcing the
host compiler settings onto the device compiler.  Maybe this should be removed
completely, but this patch just fixes a few of them.  In particular,
param_vect_partial_vector_usage is disabled by x86 and this really hurts amdgcn.

I also fixed an ambiguous else warning in the generated file by adding braces.

gcc/ChangeLog:

	* config/gcn/gcn.cc (gcn_option_override): Add note to set default for
	param_vect_partial_vector_usage to "1".
	* optc-save-gen.awk: Don't pass through options marked "NoOffload".
	* params.opt (-param=vect-epilogues-nomask): Add NoOffload.
	(-param=vect-partial-vector-usage): Likewise.
	(-param=vect-inner-loop-cost-factor): Likewise.

(cherry picked from commit b31fa1ce19542e14bea10f46240f39cb37277b80)

3 files changed, 26 insertions, 5 deletions

diff --git a/gcc/config/gcn/gcn.cc b/gcc/config/gcn/gcn.cc
index 5c0f764..d21d1f7 100644
--- a/gcc/config/gcn/gcn.cc
+++ b/gcc/config/gcn/gcn.cc
@@ -54,6 +54,7 @@
 #include "gimple.h"
 #include "cgraph.h"
 #include "case-cfn-macros.h"
+#include "opts.h"
 
 /* This file should be included last.  */
 #include "target-def.h"
@@ -183,6 +184,11 @@ gcn_option_override (void)
 
   if (flag_sram_ecc == HSACO_ATTR_DEFAULT)
     flag_sram_ecc = gcn_devices[gcn_arch].sramecc_default;
+
+  /* TODO: This seems to produce tighter loops, but the testsuites expects it
+     to be set to '2', so I'll leave it default for now.
+  SET_OPTION_IF_UNSET (&global_options, &global_options_set,
+		       param_vect_partial_vector_usage, 1);  */
 }
 
 /* }}}  */
diff --git a/gcc/optc-save-gen.awk b/gcc/optc-save-gen.awk
index a3d7e5a..31756ec 100644
--- a/gcc/optc-save-gen.awk
+++ b/gcc/optc-save-gen.awk
@@ -1313,6 +1313,12 @@ for (i = 0; i < n_opts; i++) {
 		# offloading is enabled.
 		if (flag_set_p("Target", flags[i]))
 			var_target_opt[n_opt_val] = 1;
+
+		# These options should not be passed from host to target, but
+		# are not actually target specific.
+		if (flag_set_p("NoOffload", flags[i]))
+			var_target_opt[n_opt_val] = 2;
+
 		n_opt_val++;
 	}
 }
@@ -1393,7 +1399,7 @@ for (i = 0; i < n_opt_val; i++) {
 		# Do not stream out target-specific opts if offloading is
 		# enabled.
 		if (var_target_opt[i])
-			print "  if (!lto_stream_offload_p)"
+			print "  if (!lto_stream_offload_p) {"
 		# If applicable, encode the streamed value.
 		if (var_opt_optimize_init[i]) {
 			print "  if (" var_opt_optimize_init[i] " > (" var_opt_val_type[i] ") 10)";
@@ -1403,6 +1409,8 @@ for (i = 0; i < n_opt_val; i++) {
 		} else {
 			print "  bp_pack_var_len_" sgn " (bp, ptr->" name");";
 		}
+		if (var_target_opt[i])
+			print "}"
 	}
 }
 print "  for (size_t i = 0; i < ARRAY_SIZE (ptr->explicit_mask); i++)";
@@ -1418,10 +1426,14 @@ print "                           struct cl_optimization *ptr ATTRIBUTE_UNUSED)"
 print "{";
 for (i = 0; i < n_opt_val; i++) {
 	name = var_opt_val[i]
-        if (var_target_opt[i]) {
+        if (var_target_opt[i] == 1) {
 		print "#ifdef ACCEL_COMPILER"
 		print "#error accel compiler cannot define Optimization attribute for target-specific option " name;
 		print "#else"
+	} else if (var_target_opt[i] == 2) {
+		print "#ifdef ACCEL_COMPILER"
+		print "  ptr->" name " = global_options." name ";"
+		print "#else"
 	}
 	otype = var_opt_val_type[i];
 	if (otype ~ "^const char \\**$") {
@@ -1489,6 +1501,9 @@ for (i = 0; i < n_opts; i++) {
 	if (flag_set_p("Warning", flags[i]))
 		continue;
 
+	if (flag_set_p("NoOffload", flags[i]))
+		continue;
+
 	if (name in checked_options)
 		continue;
 	checked_options[name]++
diff --git a/gcc/params.opt b/gcc/params.opt
index a2b606f..28b47ff 100644
--- a/gcc/params.opt
+++ b/gcc/params.opt
@@ -1226,7 +1226,7 @@ Common Joined UInteger Var(param_use_canonical_types) Init(1) IntegerRange(0, 1)
 Whether to use canonical types.
 
 -param=vect-epilogues-nomask=
-Common Joined UInteger Var(param_vect_epilogues_nomask) Init(1) IntegerRange(0, 1) Param Optimization
+Common Joined UInteger Var(param_vect_epilogues_nomask) Init(1) IntegerRange(0, 1) Param Optimization NoOffload
 Enable loop epilogue vectorization using smaller vector size.
 
 -param=vect-max-layout-candidates=
@@ -1246,11 +1246,11 @@ Common Joined UInteger Var(param_vect_max_version_for_alignment_checks) Init(6)
 Bound on number of runtime checks inserted by the vectorizer's loop versioning for alignment check.
 
 -param=vect-partial-vector-usage=
-Common Joined UInteger Var(param_vect_partial_vector_usage) Init(2) IntegerRange(0, 2) Param Optimization
+Common Joined UInteger Var(param_vect_partial_vector_usage) Init(2) IntegerRange(0, 2) Param Optimization NoOffload
 Controls how loop vectorizer uses partial vectors.  0 means never, 1 means only for loops whose need to iterate can be removed, 2 means for all loops.  The default value is 2.
 
 -param=vect-inner-loop-cost-factor=
-Common Joined UInteger Var(param_vect_inner_loop_cost_factor) Init(50) IntegerRange(1, 10000) Param Optimization
+Common Joined UInteger Var(param_vect_inner_loop_cost_factor) Init(50) IntegerRange(1, 10000) Param Optimization NoOffload
 The maximum factor which the loop vectorizer applies to the cost of statements in an inner loop relative to the loop being vectorized.
 
 -param=vect-induction-float=