Commit 25cd0a32 authored by wolfgang's avatar wolfgang
Browse files

[project @ 2005-01-11 22:16:07 by wolfgang]

Cleanup and additional comments for the Mac OS/AIX/powerpc64-linux adjustor
code.
parent 2128bf29
......@@ -609,97 +609,129 @@ TODO: Depending on how much allocation overhead stgMallocBytes uses for
#define OP_LO(op,lo) ((((unsigned)(op)) << 16) | (((unsigned)(lo)) & 0xFFFF))
#define OP_HI(op,hi) ((((unsigned)(op)) << 16) | (((unsigned)(hi)) >> 16))
{
AdjustorStub *adjustorStub;
int sz = 0, extra_sz, total_sz;
// from AdjustorAsm.s
// not declared as a function so that AIX-style
// fundescs can never get in the way.
extern void *adjustorCode;
{
/* The following code applies to all PowerPC and PowerPC64 platforms
whose stack layout is based on the AIX ABI.
Besides (obviously) AIX, this includes
Mac OS 9 and BeOS/PPC (may they rest in peace),
which use the 32-bit AIX ABI
powerpc64-linux,
which uses the 64-bit AIX ABI
and Darwin (Mac OS X),
which uses the same stack layout as AIX,
but no function descriptors.
The actual stack-frame shuffling is implemented out-of-line
in the function adjustorCode, in AdjustorAsm.S.
Here, we set up an AdjustorStub structure, which
is a function descriptor (on platforms that have function
descriptors) or a short piece of stub code (on Darwin) to call
adjustorCode with a pointer to the AdjustorStub struct loaded
into register r2.
One nice thing about this is that there is _no_ code generated at
runtime on the platforms that have function descriptors.
*/
AdjustorStub *adjustorStub;
int sz = 0, extra_sz, total_sz;
// from AdjustorAsm.s
// not declared as a function so that AIX-style
// fundescs can never get in the way.
extern void *adjustorCode;
#ifdef FUNDESCS
adjustorStub = stgMallocBytes(sizeof(AdjustorStub), "createAdjustor");
adjustorStub = stgMallocBytes(sizeof(AdjustorStub), "createAdjustor");
#else
adjustorStub = mallocBytesRWX(sizeof(AdjustorStub));
adjustorStub = mallocBytesRWX(sizeof(AdjustorStub));
#endif
adjustor = adjustorStub;
adjustorStub->code = (void*) &adjustorCode;
adjustor = adjustorStub;
adjustorStub->code = (void*) &adjustorCode;
#ifdef FUNDESCS
// function descriptors are a cool idea.
// We don't need to generate any code at runtime.
adjustorStub->toc = adjustorStub;
// function descriptors are a cool idea.
// We don't need to generate any code at runtime.
adjustorStub->toc = adjustorStub;
#else
// no function descriptors :-(
// We need to do things "by hand".
// no function descriptors :-(
// We need to do things "by hand".
#if defined(powerpc_TARGET_ARCH)
// lis r2, hi(adjustorStub)
adjustorStub->lis = OP_HI(0x3c40, adjustorStub);
// ori r2, r2, lo(adjustorStub)
adjustorStub->ori = OP_LO(0x6042, adjustorStub);
// lwz r0, code(r2)
adjustorStub->lwz = OP_LO(0x8002, (char*)(&adjustorStub->code)
- (char*)adjustorStub);
// mtctr r0
adjustorStub->mtctr = 0x7c0903a6;
// bctr
adjustorStub->bctr = 0x4e800420;
// lis r2, hi(adjustorStub)
adjustorStub->lis = OP_HI(0x3c40, adjustorStub);
// ori r2, r2, lo(adjustorStub)
adjustorStub->ori = OP_LO(0x6042, adjustorStub);
// lwz r0, code(r2)
adjustorStub->lwz = OP_LO(0x8002, (char*)(&adjustorStub->code)
- (char*)adjustorStub);
// mtctr r0
adjustorStub->mtctr = 0x7c0903a6;
// bctr
adjustorStub->bctr = 0x4e800420;
#else
barf("adjustor creation not supported on this platform");
barf("adjustor creation not supported on this platform");
#endif
// Flush the Instruction cache:
// Flush the Instruction cache:
{
int n = sizeof(AdjustorStub)/sizeof(unsigned);
unsigned *p = (unsigned*)adjustor;
while(n--)
{
int n = sizeof(AdjustorStub)/sizeof(unsigned);
unsigned *p = (unsigned*)adjustor;
while(n--)
{
__asm__ volatile ("dcbf 0,%0\n\tsync\n\ticbi 0,%0"
: : "r" (p));
p++;
}
__asm__ volatile ("sync\n\tisync");
__asm__ volatile ("dcbf 0,%0\n\tsync\n\ticbi 0,%0"
: : "r" (p));
p++;
}
__asm__ volatile ("sync\n\tisync");
}
#endif
printf("createAdjustor: %s\n", typeString);
while(*typeString)
{
char t = *typeString++;
// Calculate the size of the stack frame, in words.
while(*typeString)
{
char t = *typeString++;
switch(t)
{
#if defined(powerpc64_TARGET_ARCH)
case 'd': sz += 1; break;
case 'l': sz += 1; break;
#else
case 'd': sz += 2; break;
case 'l': sz += 2; break;
switch(t)
{
#if defined(powerpc_TARGET_ARCH)
// on 32-bit platforms, Double and Int64 occupy two words.
case 'd':
case 'l':
sz += 2;
break;
#endif
case 'f': sz += 1; break;
case 'i': sz += 1; break;
}
// everything else is one word.
default:
sz += 1;
}
extra_sz = sz - 8;
if(extra_sz < 0)
extra_sz = 0;
total_sz = (6 /* linkage area */
+ 8 /* minimum parameter area */
+ 2 /* two extra arguments */
+ extra_sz)*sizeof(StgWord);
// align to 16 bytes.
// AIX only requires 8 bytes, but who cares?
total_sz = (total_sz+15) & ~0xF;
adjustorStub->hptr = hptr;
adjustorStub->wptr = wptr;
adjustorStub->negative_framesize = -total_sz;
adjustorStub->extrawords_plus_one = extra_sz + 1;
}
// The first eight words of the parameter area
// are just "backing store" for the parameters passed in
// the GPRs. extra_sz is the number of words beyond those first
// 8 words.
extra_sz = sz - 8;
if(extra_sz < 0)
extra_sz = 0;
// Calculate the total size of the stack frame.
total_sz = (6 /* linkage area */
+ 8 /* minimum parameter area */
+ 2 /* two extra arguments */
+ extra_sz)*sizeof(StgWord);
// align to 16 bytes.
// AIX only requires 8 bytes, but who cares?
total_sz = (total_sz+15) & ~0xF;
// Fill in the information that adjustorCode in AdjustorAsm.S
// will use to create a new stack frame with the additional args.
adjustorStub->hptr = hptr;
adjustorStub->wptr = wptr;
adjustorStub->negative_framesize = -total_sz;
adjustorStub->extrawords_plus_one = extra_sz + 1;
}
#elif defined(ia64_TARGET_ARCH)
/*
......
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