Changeset 5572

Timestamp:

Dec 3, 2006, 1:28:35 AM (18 years ago)

Author:

Gary Byers

Message:

Do vector bounds checking by clearing the low byte of the header, shifting
it right, and comparing the index to that. (It's not reliable to shift
the index left.)

File:

• trunk/ccl/lisp-kernel/x86-spentry64.s (modified) (4 diffs)

trunk/ccl/lisp-kernel/x86-spentry64.s

@@ -172 +172 @@
         __(je,pt 1f)
         __(uuo_error_reg_not_fixnum(Rarg_z))
-1:      __(movq %arg_z,%imm0)
-        __(shlq $num_subtag_bits-fixnumshift,%imm0)
-        __(movb $-1,%imm0_b)
-        __(cmpq misc_header_offset(%arg_y),%imm0)
-        __(jb 2f)
+1:      __(movq misc_header_offset(%arg_y),%imm0)
+        __(xorb %imm0_b,%imm0_b)
+        __(shrq $num_subtag_bits-fixnumshift,%imm0)
+        __(cmpq %imm0,%arg_z)
+        __(jb,pt 2f)
         __(uuo_error_vector_bounds(Rarg_z,Rarg_y))
 2:      __(movb misc_subtag_offset(%arg_y),%imm1_b)
@@ -578 +578 @@
         __(je,pt 1f)
         __(uuo_error_reg_not_fixnum(Rarg_z))
-1:      __(movq %arg_z,%imm0)
-        __(shlq $num_subtag_bits-fixnumshift,%imm0)
-        __(movb $255,%imm0_b)
-        __(cmpq misc_header_offset(%arg_y),%imm0)
+1:      __(movq misc_header_offset(%arg_y),%imm0)
+        __(xorb %imm0_b,%imm0_b)
+        __(shrq $num_subtag_bits-fixnumshift,%imm0)
+        __(cmpq %imm0,%arg_z)
         __(jb 2f)
         __(uuo_error_vector_bounds(Rarg_z,Rarg_y))
@@ -597 +597 @@
         __(je,pt 1f)
         __(uuo_error_reg_not_fixnum(Rarg_y))
-1:      __(movq %arg_y,%imm0)
-        __(shlq $num_subtag_bits-fixnumshift,%imm0)
-        __(movb $255,%imm0_b)
-        __(cmpq misc_header_offset(%arg_x),%imm0)
+1:      __(movq misc_header_offset(%arg_x),%imm0)
+        __(xorb %imm0_b,%imm0_b)
+        __(shrq $num_subtag_bits-fixnumshift,%imm0)
+        __(cmpq %imm0,%arg_y)
         __(jb 2f)
         __(uuo_error_vector_bounds(Rarg_y,Rarg_x))
@@ -616 +616 @@
         __(je,pt 1f)
         __(uuo_error_reg_not_fixnum(Rarg_y))
-1:      __(movq %arg_y,%imm0)
-        __(shlq $num_subtag_bits-fixnumshift,%imm0)
-        __(movb $255,%imm0_b)
-        __(cmpq misc_header_offset(%arg_x),%imm0)
+1:      __(movq misc_header_offset(%arg_x),%imm0)
+        __(xorb %imm0_b,%imm0_b)
+        __(shrq $num_subtag_bits-fixnumshift,%imm0)
+        __(cmpq %imm0,%arg_y)
         __(jb 2f)
         __(uuo_error_vector_bounds(Rarg_y,Rarg_x))