duskos

commit 8f6bdeded1bb580d98408d823d39da293f4fdd31
parent 30d0c77ad9412022cdee7bca84978eeb4eeab47f
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Thu, 13 Oct 2022 20:45:24 -0400

cc/vm/i386: fix opwidth bug

Diffstat:
M
fs/cc/vm/i386.fs
 | 
15
++++++++++++---
M
fs/tests/cc/cc.fs
 | 
1
+
M
fs/tests/cc/test.c
 | 
6
++++++

3 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/fs/cc/vm/i386.fs b/fs/cc/vm/i386.fs
@@ -80,7 +80,10 @@ struct+[ VMOp
       VM_*STACKFRAME of = V1 :>reg endof
       VM_*ARGSFRAME of = V1 :>reg endof
       VM_*REGISTER of =
-        V1 arg r! V1 arg r! 0 d) movclr, VM_REGISTER V1 to loc endof
+        V1 type typesize 4 < if
+          V1 :typesz! dx V1 arg r! 0 d) movclr, V1 arg r! dx mov, else
+          V1 arg r! V1 arg r! 0 d) mov, then
+        VM_REGISTER V1 to loc endof
     endcase rdrop ;
 
   \ Before doing an operation on two operands, we verify that they are
@@ -104,6 +107,12 @@ struct+[ VMOp
 \ Verify that we're in "neutral" position with regards to registers
 : neutral# reglvl if abort" unbalanced reg allot/free" then ;
 
+\ If one op is larger than the other, copy the smaller one to a register and
+\ copy the type of the larger op to the smaller.
+: harmonizeops vmop type typesize vmop^ type typesize 2dup < if
+    2drop vmop :>reg vmop^ type to vmop type else > if
+    vmop^ :>reg vmop type to vmop^ type then then ;
+
 \ Code generation - Functions, calls, ret, pspush, pspop
 
 \ generate function prelude code by allocating "locsz" bytes on RS.
@@ -148,7 +157,7 @@ struct+[ VMOp
 
 \ Code generation - Binary ops
 : binop doer ' , does> ( 'w ) @
-  vmop :>res vmop :compileDest vmop^ :compile execute vmop^ :init ;
+  vmop :>res harmonizeops vmop :compile vmop^ :compile execute vmop^ :init ;
 binop vm+, add,
 binop vm-, sub,
 binop vm&, and,
@@ -218,7 +227,7 @@ unaryop vmnot, not, ( ~ )
 
 : vm+n, ( n -- ) vmop :loclo VM_CONSTANT = if
     to+ vmop arg
-    else vmop :compileDest i) add, then ;
+    else vmop :>res vmop :compile i) add, then ;
 
 \ post-inc/dec op1
 \ It's a bit complicated here. Before we inc/dec, we need a copy of the current
diff --git a/fs/tests/cc/cc.fs b/fs/tests/cc/cc.fs
@@ -70,6 +70,7 @@ globdata 4 + 16b @ 42 #eq
 '2' binop2 44 #eq
 binop3 $605 #eq
 binop5 1 #eq
+binop6 $1fe #eq
 structop1 44 #eq
 structop2 45 #eq
 opwidth1 42 #eq
diff --git a/fs/tests/cc/test.c b/fs/tests/cc/test.c
@@ -291,6 +291,12 @@ int binop5() {
     int x = 2;
     return x && 1;
 }
+// the i386 VM performed this add in 8b mode, not carrying the $100.
+unsigned int binop6() {
+    unsigned int x = $ff;
+    unsigned char y = $ff;
+    return x + y;
+}
 short structop1() {
     globdata.bar += 2;
     return globdata.bar;