[project @ 2000-02-03 18:01:03 by sewardj]

Fix x86 NCG so the compiler can compile itself `-O':

-- Implement fake x86 insn GITOD/GITOF.
-- Implement primops ReadMutVarOp and WriteMutVarOp.
-- Pro tem, disable use of %eax as a spill temp.
-- Clarify wording of Rules of the Game comment in MachCode.

diff --git a/ghc/compiler/nativeGen/AsmCodeGen.lhs b/ghc/compiler/nativeGen/AsmCodeGen.lhs
index fe2fcbf..e3a16c3 100644 (file)
--- a/ghc/compiler/nativeGen/AsmCodeGen.lhs
+++ b/ghc/compiler/nativeGen/AsmCodeGen.lhs
@@ -89,6 +89,7 @@ nativeCodeGen absC us
          insns          = initUs_ us1 (codeGen stixOpt)
          debug_stix     = vcat (map pprStixTrees stixOpt)
      in 
+         trace "--------- native code generator ---------"
          (debug_stix, insns)
 \end{code}
 

diff --git a/ghc/compiler/nativeGen/MachCode.lhs b/ghc/compiler/nativeGen/MachCode.lhs
index fb88fc6..820b5ae 100644 (file)
--- a/ghc/compiler/nativeGen/MachCode.lhs
+++ b/ghc/compiler/nativeGen/MachCode.lhs
@@ -2743,7 +2743,7 @@ The Rules of the Game are:
 * You cannot assume anything about the destination register dst;
   it may be anything, includind a fixed reg.
 
-* You may compute a value into a fixed reg, but you may not 
+* You may compute an operand into a fixed reg, but you may not 
   subsequently change the contents of that fixed reg.  If you
   want to do so, first copy the value either to a temporary
   or into dst.  You are free to modify dst even if it happens
@@ -2752,8 +2752,9 @@ The Rules of the Game are:
 * You cannot assume that a fixed reg will stay live over an
   arbitrary computation.  The same applies to the dst reg.
 
-* Temporary regs obtained from getNewRegNCG are distinct from
-  all other regs, and stay live over arbitrary computations.
+* Temporary regs obtained from getNewRegNCG are distinct from 
+  each other and from all other regs, and stay live over 
+  arbitrary computations.
 
 \begin{code}
 

diff --git a/ghc/compiler/nativeGen/NOTES b/ghc/compiler/nativeGen/NOTES
index 9927b6e..5f76d69 100644 (file)
--- a/ghc/compiler/nativeGen/NOTES
+++ b/ghc/compiler/nativeGen/NOTES
@@ -26,6 +26,10 @@ All these bugs are for x86; I don't know about sparc/alpha.
    by the OS), and (2) if a signal should be handled on that stack
    during argument construction, the args will get silently trashed.
 
+   Currently, implementation of GITOF et al use the stack, so are
+   incompatible with current ccall implementation.  When the latter
+   is fixed, GITOF et al should present no problem.
+
 -- nofib/real/hidden gets slightly different FP answers from the
    via-C route; possibly due to exp/log not being done in-line.
 

diff --git a/ghc/compiler/nativeGen/PprMach.lhs b/ghc/compiler/nativeGen/PprMach.lhs
index 23f81a9..a3fe5de 100644 (file)
--- a/ghc/compiler/nativeGen/PprMach.lhs
+++ b/ghc/compiler/nativeGen/PprMach.lhs
@@ -1003,9 +1003,11 @@ pprInstr g@(GDTOI src dst)
    = pprG g bogus
 
 pprInstr g@(GITOF src dst) 
-   = pprG g bogus
+   = pprInstr (GITOD src dst)
 pprInstr g@(GITOD src dst) 
-   = pprG g bogus
+   = pprG g (hcat [gtab, text "pushl ", pprReg L src, 
+                   text " ; ffree %st(7); fildl (%esp) ; ",
+                   gpop dst 1, text " ; addl $4,%esp"])
 
 pprInstr g@(GCMP sz src1 src2) 
    = pprG g (hcat [gtab, text "pushl %eax ; ",

diff --git a/ghc/compiler/nativeGen/RegAllocInfo.lhs b/ghc/compiler/nativeGen/RegAllocInfo.lhs
index 53d651e..23aef3b 100644 (file)
--- a/ghc/compiler/nativeGen/RegAllocInfo.lhs
+++ b/ghc/compiler/nativeGen/RegAllocInfo.lhs
@@ -581,8 +581,13 @@ findReservedRegs instrs
     -- dire straits (but still correct): see if we can bag %eax and %edx
     ++ if   any hasFixedEAXorEDX instrs
        then []  -- bummer
-       else [ [ecx,edx,fake4,fake5],
-              [ecx,edx,eax,fake4,fake5] ]
+       else --[ [ecx,edx,fake4,fake5],
+            --  [ecx,edx,eax,fake4,fake5] ]
+            -- pro tem, don't use %eax until we institute a check that
+            -- instrs doesn't do a CALL insn, since that effectively
+            -- uses %eax in a fixed way
+            [ [ecx,edx,fake4,fake5] ]
+
     )
 #endif
 \end{code}

diff --git a/ghc/compiler/nativeGen/StixPrim.lhs b/ghc/compiler/nativeGen/StixPrim.lhs
index 2d86439..353bd33 100644 (file)
--- a/ghc/compiler/nativeGen/StixPrim.lhs
+++ b/ghc/compiler/nativeGen/StixPrim.lhs
@@ -256,6 +256,27 @@ primCode [lhs] DataToTagOp [arg]
     returnUs (\xs -> assign : xs)
 \end{code}
 
+MutVars are pretty simple.
+#define writeMutVarzh(a,v)       (P_)(((StgMutVar *)(a))->var)=(v)
+
+\begin{code}
+primCode [] WriteMutVarOp [aa,vv]
+   = let aa_s      = amodeToStix aa
+         vv_s      = amodeToStix vv
+         var_field = StIndex PtrRep aa_s fixedHS
+         assign    = StAssign PtrRep (StInd PtrRep var_field) vv_s
+     in
+     returnUs (\xs -> assign : xs)
+
+primCode [rr] ReadMutVarOp [aa]
+   = let aa_s      = amodeToStix aa
+         rr_s      = amodeToStix rr
+         var_field = StIndex PtrRep aa_s fixedHS
+         assign    = StAssign PtrRep rr_s (StInd PtrRep var_field)
+     in
+     returnUs (\xs -> assign : xs)
+\end{code}
+
 Now the more mundane operations.
 
 \begin{code}