From: David Given <dg@cowlark.com>
Date: Fri, 14 Oct 2016 21:12:29 +0000 (+0200)
Subject: Fix stupid issue where hop output registers were being overwritten, leading to
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=bb53a7fb5123ec25a391396d00711fd29790550f;p=ack.git

Fix stupid issue where hop output registers were being overwritten, leading to
invalid SSA form.
---

diff --git a/mach/proto/mcg/pass_instructionselection.c b/mach/proto/mcg/pass_instructionselection.c
index 7e38efe4b..e8c9c453f 100644
--- a/mach/proto/mcg/pass_instructionselection.c
+++ b/mach/proto/mcg/pass_instructionselection.c
@@ -181,26 +181,26 @@ static struct insn* walk_instructions(struct burm_node* node, int goal)
 
         if (!insn->insndata->is_fragment)
         {
-            struct vreg* vreg = NULL;
+            insn->hop = current_hop = new_hop(current_bb, insn->ir);
+            emit(insn);
 
-            switch (node->label)
+            if (!current_hop->output)
             {
-                case ir_to_esn(IR_REG, 1):
-                case ir_to_esn(IR_REG, 2):
-                case ir_to_esn(IR_REG, 4):
-                case ir_to_esn(IR_REG, 8):
-                    vreg = node->ir->result;
-                    break;
-
-                case ir_to_esn(IR_NOP, 0):
-                    vreg = node->left->ir->result;
-                    break;
+                switch (node->label)
+                {
+                    case ir_to_esn(IR_REG, 1):
+                    case ir_to_esn(IR_REG, 2):
+                    case ir_to_esn(IR_REG, 4):
+                    case ir_to_esn(IR_REG, 8):
+                        current_hop->output = node->ir->result;
+                        break;
+
+                    case ir_to_esn(IR_NOP, 0):
+                        current_hop->output = node->left->ir->result;
+                        break;
+                }
             }
 
-            insn->hop = current_hop = new_hop(current_bb, insn->ir);
-            current_hop->output = vreg;
-            emit(insn);
-
             hop_print('I', current_hop);
             array_append(&current_bb->hops, current_hop);