[patch] fix pr31937 soft-float for libffi ppc 32-bit

[patch] fix pr31937 soft-float for libffi ppc 32-bit

[Andreas Tobler]

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Hi all,
this patch adds soft float support for libffi-ppc 32-bit. Tested by 
Martin and me on a ppc-405 target. Libffi and libjava, on trunk.
No negative influence on real ppc with fpu.

This patch 'fixes' pr31937.

The patch itself makes sure not to store float/double in the asm part. 
Also, the patch 'changes' the ABI to store float as UINT32 and double as 
UINT64.

Ok for trunk?

Thanks,
Andreas

2007-11-06  Andreas Tobler  <a.tobler@schweiz.org>

	PR libffi/31937
	* src/powerpc/ffi.c (enum): Add __NO_FPRS__, handle soft-float support.
	(ffi_prep_args_SYSV): Handle __NO_FPRS__.
	(ffi_prep_cif_machdep): Likewise.
	(ffi_closure_helper_SYSV): Likewise.
	* src/powerpc/ppc_closure.S: Make sure not to store float/double
	on SOFT_FLOAT archs.

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Index: src/powerpc/ppc_closure.S
===================================================================
--- src/powerpc/ppc_closure.S	(revision 129874)
+++ src/powerpc/ppc_closure.S	(working copy)
@@ -28,6 +28,7 @@
 	stw   %r9, 40(%r1)
 	stw   %r10,44(%r1)
 
+#ifndef __NO_FPRS__
 	# next save fpr 1 to fpr 8 (aligned to 8)
 	stfd  %f1, 48(%r1)
 	stfd  %f2, 56(%r1)
@@ -37,6 +38,7 @@
 	stfd  %f6, 88(%r1)
 	stfd  %f7, 96(%r1)
 	stfd  %f8, 104(%r1)
+#endif
 
 	# set up registers for the routine that actually does the work
 	# get the context pointer from the trampoline
Index: src/powerpc/ffi.c
===================================================================
--- src/powerpc/ffi.c	(revision 129874)
+++ src/powerpc/ffi.c	(working copy)
@@ -51,7 +51,11 @@
 /* About the SYSV ABI.  */
 enum {
   NUM_GPR_ARG_REGISTERS = 8,
+#ifndef __NO_FPRS__
   NUM_FPR_ARG_REGISTERS = 8
+#else
+  NUM_FPR_ARG_REGISTERS = 0
+#endif
 };
 enum { ASM_NEEDS_REGISTERS = 4 };
 
@@ -117,7 +121,9 @@
 
   int i;
   ffi_type **ptr;
+#ifndef __NO_FPRS__
   double double_tmp;
+#endif
   union {
     void **v;
     char **c;
@@ -163,6 +169,7 @@
     {
       switch ((*ptr)->type)
 	{
+#ifndef __NO_FPRS__
 	case FFI_TYPE_FLOAT:
 	  double_tmp = **p_argv.f;
 	  if (fparg_count >= NUM_FPR_ARG_REGISTERS)
@@ -195,6 +202,7 @@
 	  fparg_count++;
 	  FFI_ASSERT (flags & FLAG_FP_ARGUMENTS);
 	  break;
+#endif
 
 #if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE
 	case FFI_TYPE_LONGDOUBLE:
@@ -230,6 +238,9 @@
 
 	case FFI_TYPE_UINT64:
 	case FFI_TYPE_SINT64:
+#ifdef __NO_FPRS__
+	case FFI_TYPE_DOUBLE:
+#endif
 	  if (intarg_count == NUM_GPR_ARG_REGISTERS-1)
 	    intarg_count++;
 	  if (intarg_count >= NUM_GPR_ARG_REGISTERS)
@@ -292,6 +303,9 @@
 	case FFI_TYPE_UINT32:
 	case FFI_TYPE_SINT32:
 	case FFI_TYPE_POINTER:
+#ifdef __NO_FPRS__
+	case FFI_TYPE_FLOAT:
+#endif
 	  gprvalue = **p_argv.ui;
 
 	putgpr:
@@ -596,7 +610,9 @@
       flags |= FLAG_RETURNS_64BITS;
       /* Fall through.  */
     case FFI_TYPE_FLOAT:
+#ifndef __NO_FPRS__
       flags |= FLAG_RETURNS_FP;
+#endif
       break;
 
     case FFI_TYPE_UINT64:
@@ -658,6 +674,7 @@
       {
 	switch ((*ptr)->type)
 	  {
+#ifndef __NO_FPRS__
 	  case FFI_TYPE_FLOAT:
 	    fparg_count++;
 	    /* floating singles are not 8-aligned on stack */
@@ -680,8 +697,12 @@
 	      intarg_count++;
 	    break;
 
+#endif
 	  case FFI_TYPE_UINT64:
 	  case FFI_TYPE_SINT64:
+#ifdef __NO_FPRS__
+	  case FFI_TYPE_DOUBLE:
+#endif
 	    /* 'long long' arguments are passed as two words, but
 	       either both words must fit in registers or both go
 	       on the stack.  If they go on the stack, they must
@@ -922,7 +943,9 @@
   long             nf;   /* number of floating registers already used */
   long             ng;   /* number of general registers already used */
   ffi_cif *        cif;
+#ifndef __NO_FPRS__
   double           temp;
+#endif
   unsigned         size;
 
   cif = closure->cif;
@@ -994,6 +1017,9 @@
 	case FFI_TYPE_SINT32:
 	case FFI_TYPE_UINT32:
 	case FFI_TYPE_POINTER:
+#ifdef __NO_FPRS__
+	case FFI_TYPE_FLOAT:
+#endif
 	  /* there are 8 gpr registers used to pass values */
 	  if (ng < 8)
 	    {
@@ -1029,6 +1055,9 @@
 
 	case FFI_TYPE_SINT64:
 	case FFI_TYPE_UINT64:
+#ifdef __NO_FPRS__
+	case FFI_TYPE_DOUBLE:
+#endif
 	  /* passing long long ints are complex, they must
 	   * be passed in suitable register pairs such as
 	   * (r3,r4) or (r5,r6) or (r6,r7), or (r7,r8) or (r9,r10)
@@ -1059,6 +1088,7 @@
 	    }
 	  break;
 
+#ifndef __NO_FPRS__
 	case FFI_TYPE_FLOAT:
 	  /* unfortunately float values are stored as doubles
 	   * in the ffi_closure_SYSV code (since we don't check
@@ -1106,6 +1136,7 @@
 	    }
 	  break;
 
+#endif
 #if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE
 	case FFI_TYPE_LONGDOUBLE:
 	  if (cif->abi != FFI_LINUX)
@@ -1149,7 +1180,21 @@
 	   && cif->abi != FFI_LINUX)
     return FFI_TYPE_STRUCT;
 #endif
+#ifdef __NO_FPRS__
+  switch (cif->rtype->type)
+    {
+    case FFI_TYPE_FLOAT:
+      return FFI_TYPE_UINT32;
+      break;
+    case FFI_TYPE_DOUBLE:
+      return FFI_TYPE_UINT64;
+      break;
+    default:
+      return cif->rtype->type;
+    }
+#else
   return cif->rtype->type;
+#endif
 }
 
 int FFI_HIDDEN ffi_closure_helper_LINUX64 (ffi_closure *, void *,

Re: [patch] fix pr31937 soft-float for libffi ppc 32-bit

[David Daney]

Andreas Tobler wrote:
> Hi all,
> this patch adds soft float support for libffi-ppc 32-bit. Tested by 
> Martin and me on a ppc-405 target. Libffi and libjava, on trunk.
> No negative influence on real ppc with fpu.
> 
> This patch 'fixes' pr31937.
> 
> The patch itself makes sure not to store float/double in the asm part. 
> Also, the patch 'changes' the ABI to store float as UINT32 and double as 
> UINT64.
> 
> Ok for trunk?
> 
> Thanks,
> Andreas
> 
> 2007-11-06  Andreas Tobler  <a.tobler@schweiz.org>
> 
>     PR libffi/31937
>     * src/powerpc/ffi.c (enum): Add __NO_FPRS__, handle soft-float support.
>     (ffi_prep_args_SYSV): Handle __NO_FPRS__.
>     (ffi_prep_cif_machdep): Likewise.
>     (ffi_closure_helper_SYSV): Likewise.
>     * src/powerpc/ppc_closure.S: Make sure not to store float/double
>     on SOFT_FLOAT archs.
> 
> 

Instead of pretending that there is a single ABI that happens to change 
depending on the options passed to the compiler (hard or soft float), 
you could explicitly support both hard and soft float ABIs in libffi.

This wouldn't necessarily make libjava work any better, but it would 
give you the flexibility of being able to use a hard-float libffi to 
call between hard-fload and soft-float ABI code.

FWIW, this is what I did for MIPS libffi.

David Daney

Re: [patch] fix pr31937 soft-float for libffi ppc 32-bit

[Andreas Tobler]

David Daney wrote:

> Instead of pretending that there is a single ABI that happens to change 
> depending on the options passed to the compiler (hard or soft float), 
> you could explicitly support both hard and soft float ABIs in libffi.
> 
> This wouldn't necessarily make libjava work any better, but it would 
> give you the flexibility of being able to use a hard-float libffi to 
> call between hard-fload and soft-float ABI code.
> 
> FWIW, this is what I did for MIPS libffi.

For the record, I took this as suggestion to rework the patch and I 
found during this work that I also have to bring support for 
long-double-128 soft-float.
This is a bit tricky, so I will take some time.

The soft-float long-double-64 support is implemented now in the way 
David suggested. (I hope it is ;)

The soft-float long-double-128 is on the way to come.

Just fyi.

Andreas