[pypy-svn] r41112 - pypy/dist/pypy/jit/codegen/i386

[arigo at codespeak.net]

Author: arigo
Date: Thu Mar 22 19:01:16 2007
New Revision: 41112

Modified:
   pypy/dist/pypy/jit/codegen/i386/operation.py
   pypy/dist/pypy/jit/codegen/i386/regalloc.py
Log:
Register allocation subtleties in the 'shift' code... as usual.


Modified: pypy/dist/pypy/jit/codegen/i386/operation.py
==============================================================================
--- pypy/dist/pypy/jit/codegen/i386/operation.py	(original)
+++ pypy/dist/pypy/jit/codegen/i386/operation.py	Thu Mar 22 19:01:16 2007
@@ -442,7 +442,6 @@
 
     def generate(self, allocator):
         op2 = allocator.get_operand(self.y)
-        holds_ecx = False
         mc = allocator.mc
         if isinstance(op2, IMM32):
             n = op2.value
@@ -461,7 +460,6 @@
         else:
             if self.countmax31:
                 allocator.clobber(ecx)
-                holds_ecx = True
                 op2 = allocator.get_operand(self.y)
                 mc.MOV(ecx, imm8(31))
                 mc.CMP(op2, ecx)
@@ -469,13 +467,12 @@
                 allocator.release(self.y)
             elif op2 != ecx:
                 allocator.clobber(ecx)
-                holds_ecx = True
                 op2 = allocator.get_operand(self.y)
                 mc.MOV(ecx, op2)
                 allocator.release(self.y)
             else:
-                op2 = allocator.grab_operand(self.y)
-                assert op2 == ecx
+                allocator.release(self.y)
+                allocator.clobber(ecx)    # but self.y is still in there
             count = cl
 
         srcop = allocator.get_operand(self.x)
@@ -492,10 +489,7 @@
                 mc.CMP(ecx, imm8(32))
                 mc.SBB(ecx, ecx)
                 mc.AND(dstop, ecx)
-            if holds_ecx:
-                allocator.end_clobber(ecx)
-            else:
-                allocator.release(self.y)
+            allocator.end_clobber(ecx)
 
 class OpIntLShift(OpShift):
     opname = 'int_lshift', 'uint_lshift'
@@ -597,10 +591,11 @@
             op = allocator.get_operand(self.gv_condition)
             mc.CMP(op, imm(0))
             cc = Conditions['NE']
-        allocator.release(self.gv_condition)
         operands = []
         for gv in targetbuilder.inputargs_gv:
             operands.append(allocator.get_operand(gv))
+        allocator.release(self.gv_condition)
+        for gv in targetbuilder.inputargs_gv:
             allocator.release(gv)
         if self.negate:
             cc = cond_negate(cc)
@@ -627,6 +622,7 @@
         operands = []
         for v in self.args_gv:
             operands.append(allocator.get_operand(v))
+        for v in self.args_gv:
             allocator.release(v)
         lbl = self.lbl
         lbl.targetaddr = allocator.mc.tell()
@@ -655,7 +651,6 @@
                 stackargs_i.append(i)
             else:
                 mc.MOV(mem(esp, WORD * i), srcop)
-                allocator.release(args_gv[i])
 
         allocator.clobber3(eax, edx, ecx)
         allocator.reserve_extra_stack(len(args_gv))
@@ -666,7 +661,6 @@
                 srcop = allocator.get_operand(args_gv[i])
                 mc.MOV(tmp, srcop)
                 mc.MOV(mem(esp, WORD * i), tmp)
-                allocator.release(args_gv[i])
 
         fnop = allocator.get_operand(self.gv_fnptr)
         if isinstance(fnop, IMM32):
@@ -675,6 +669,8 @@
             mc.CALL(fnop)
 
         allocator.release(self.gv_fnptr)
+        for v in args_gv:
+            allocator.release(v)
         allocator.end_clobber(eax)
         allocator.end_clobber(edx)
         allocator.end_clobber(ecx)

Modified: pypy/dist/pypy/jit/codegen/i386/regalloc.py
==============================================================================
--- pypy/dist/pypy/jit/codegen/i386/regalloc.py	(original)
+++ pypy/dist/pypy/jit/codegen/i386/regalloc.py	Thu Mar 22 19:01:16 2007
@@ -313,7 +313,11 @@
             self.registers_pinned |= loc.bitmask
 
     def release(self, v):
-        """Stop using argument 'v'.  Must be called for each used argument."""
+        """Stop using argument 'v'.  Must be called for each used argument.
+        Warning: if an operation uses v1 and v2, and if v1 could be equal to
+        v2, then calling release(v1) will also immediately release(v2)...
+        The best is to call release() on all operands at once.
+        """
         ok = self.lastuse(v) and v in self.vars_in_use
         if ok:
             self._no_longer_in_use(v)