From c57173b69a617edf59ed2e73edda183e7aebf05e Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Thu, 1 Oct 2015 06:59:00 +0930 Subject: [PATCH] [RS6000] Correct powerpc sysv stack argument accounting ppc32 starts using the stack for integer arg passing when we run out of integer arg passing registers. Similarly, we start using the stack for floating point args when we run out of floating point registers. The decision on where an integer arg goes does not depend on number of floating point args, nor does the decision on where a floating point arg goes depend on number of integer args. Alignment of stack args also simply depends on number of stack args. This patch untangles the horrible mess we had, with intarg_count being wrongly used to count both integer args and stack words. * src/powerpc/ffi_sysv.c (ffi_prep_cif_sysv_core): Count fprs, gprs, and stack words separately. (ffi_prep_args_SYSV): Similarly. From-SVN: r228307 --- libffi/ChangeLog | 6 + libffi/src/powerpc/ffi_sysv.c | 207 ++++++++++++++++------------------ 2 files changed, 104 insertions(+), 109 deletions(-) diff --git a/libffi/ChangeLog b/libffi/ChangeLog index 19a6433f038..c7ade43d0d0 100644 --- a/libffi/ChangeLog +++ b/libffi/ChangeLog @@ -1,3 +1,9 @@ +2015-10-01 Alan Modra + + * src/powerpc/ffi_sysv.c (ffi_prep_cif_sysv_core): Count fprs, + gprs, and stack words separately. + (ffi_prep_args_SYSV): Similarly. + 2015-05-13 Michael Haubenwallner * Makefile.in: Regenerated with automake-1.11.6. diff --git a/libffi/src/powerpc/ffi_sysv.c b/libffi/src/powerpc/ffi_sysv.c index 646c340d5ad..4078e751162 100644 --- a/libffi/src/powerpc/ffi_sysv.c +++ b/libffi/src/powerpc/ffi_sysv.c @@ -93,7 +93,7 @@ ffi_prep_cif_sysv_core (ffi_cif *cif) { ffi_type **ptr; unsigned bytes; - unsigned i, fparg_count = 0, intarg_count = 0; + unsigned i, fpr_count = 0, gpr_count = 0, stack_count = 0; unsigned flags = cif->flags; unsigned struct_copy_size = 0; unsigned type = cif->rtype->type; @@ -155,7 +155,7 @@ ffi_prep_cif_sysv_core (ffi_cif *cif) flags |= FLAG_RETURNS_SMST; break; } - intarg_count++; + gpr_count++; flags |= FLAG_RETVAL_REFERENCE; /* Fall through. */ case FFI_TYPE_VOID: @@ -182,24 +182,41 @@ ffi_prep_cif_sysv_core (ffi_cif *cif) { #if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE case FFI_TYPE_LONGDOUBLE: - fparg_count++; - /* Fall thru */ + if (fpr_count >= NUM_FPR_ARG_REGISTERS - 1) + { + fpr_count = NUM_FPR_ARG_REGISTERS; + /* 8-byte align long doubles. */ + stack_count += stack_count & 1; + stack_count += 4; + } + else + fpr_count += 2; +#ifdef __NO_FPRS__ + return FFI_BAD_ABI; #endif + break; +#endif + case FFI_TYPE_DOUBLE: - fparg_count++; - /* If this FP arg is going on the stack, it must be - 8-byte-aligned. */ - if (fparg_count > NUM_FPR_ARG_REGISTERS - && intarg_count >= NUM_GPR_ARG_REGISTERS - && intarg_count % 2 != 0) - intarg_count++; + if (fpr_count >= NUM_FPR_ARG_REGISTERS) + { + /* 8-byte align doubles. */ + stack_count += stack_count & 1; + stack_count += 2; + } + else + fpr_count += 1; #ifdef __NO_FPRS__ return FFI_BAD_ABI; #endif break; case FFI_TYPE_FLOAT: - fparg_count++; + if (fpr_count >= NUM_FPR_ARG_REGISTERS) + /* Yes, we don't follow the ABI, but neither does gcc. */ + stack_count += 1; + else + fpr_count += 1; #ifdef __NO_FPRS__ return FFI_BAD_ABI; #endif @@ -208,11 +225,13 @@ ffi_prep_cif_sysv_core (ffi_cif *cif) case FFI_TYPE_UINT128: /* A long double in FFI_LINUX_SOFT_FLOAT can use only a set of four consecutive gprs. If we do not have enough, we - have to adjust the intarg_count value. */ - if (intarg_count >= NUM_GPR_ARG_REGISTERS - 3 - && intarg_count < NUM_GPR_ARG_REGISTERS) - intarg_count = NUM_GPR_ARG_REGISTERS; - intarg_count += 4; + have to adjust the gpr_count value. */ + if (gpr_count >= NUM_GPR_ARG_REGISTERS - 3) + gpr_count = NUM_GPR_ARG_REGISTERS; + if (gpr_count >= NUM_GPR_ARG_REGISTERS) + stack_count += 4; + else + gpr_count += 4; break; case FFI_TYPE_UINT64: @@ -225,10 +244,14 @@ ffi_prep_cif_sysv_core (ffi_cif *cif) Also, only certain register pairs can be used for passing long long int -- specifically (r3,r4), (r5,r6), (r7,r8), (r9,r10). */ - if (intarg_count == NUM_GPR_ARG_REGISTERS-1 - || intarg_count % 2 != 0) - intarg_count++; - intarg_count += 2; + gpr_count += gpr_count & 1; + if (gpr_count >= NUM_GPR_ARG_REGISTERS) + { + stack_count += stack_count & 1; + stack_count += 2; + } + else + gpr_count += 2; break; case FFI_TYPE_STRUCT: @@ -249,7 +272,10 @@ ffi_prep_cif_sysv_core (ffi_cif *cif) case FFI_TYPE_SINT8: /* Everything else is passed as a 4-byte word in a GPR, either the object itself or a pointer to it. */ - intarg_count++; + if (gpr_count >= NUM_GPR_ARG_REGISTERS) + stack_count += 1; + else + gpr_count += 1; break; default: @@ -257,22 +283,19 @@ ffi_prep_cif_sysv_core (ffi_cif *cif) } } - if (fparg_count != 0) + if (fpr_count != 0) flags |= FLAG_FP_ARGUMENTS; - if (intarg_count > 4) + if (gpr_count > 4) flags |= FLAG_4_GPR_ARGUMENTS; if (struct_copy_size != 0) flags |= FLAG_ARG_NEEDS_COPY; /* Space for the FPR registers, if needed. */ - if (fparg_count != 0) + if (fpr_count != 0) bytes += NUM_FPR_ARG_REGISTERS * sizeof (double); /* Stack space. */ - if (intarg_count > NUM_GPR_ARG_REGISTERS) - bytes += (intarg_count - NUM_GPR_ARG_REGISTERS) * sizeof (int); - if (fparg_count > NUM_FPR_ARG_REGISTERS) - bytes += (fparg_count - NUM_FPR_ARG_REGISTERS) * sizeof (double); + bytes += stack_count * sizeof (int); /* The stack space allocated needs to be a multiple of 16 bytes. */ bytes = (bytes + 15) & ~0xF; @@ -367,13 +390,13 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack) /* 'gpr_base' points at the space for gpr3, and grows upwards as we use GPR registers. */ valp gpr_base; - int intarg_count; + valp gpr_end; #ifndef __NO_FPRS__ /* 'fpr_base' points at the space for fpr1, and grows upwards as we use FPR registers. */ valp fpr_base; - int fparg_count; + valp fpr_end; #endif /* 'copy_space' grows down as we put structures in it. It should @@ -405,11 +428,11 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack) unsigned gprvalue; stacktop.c = (char *) stack + bytes; - gpr_base.u = stacktop.u - ASM_NEEDS_REGISTERS - NUM_GPR_ARG_REGISTERS; - intarg_count = 0; + gpr_end.u = stacktop.u - ASM_NEEDS_REGISTERS; + gpr_base.u = gpr_end.u - NUM_GPR_ARG_REGISTERS; #ifndef __NO_FPRS__ - fpr_base.d = gpr_base.d - NUM_FPR_ARG_REGISTERS; - fparg_count = 0; + fpr_end.d = gpr_base.d; + fpr_base.d = fpr_end.d - NUM_FPR_ARG_REGISTERS; copy_space.c = ((flags & FLAG_FP_ARGUMENTS) ? fpr_base.c : gpr_base.c); #else copy_space.c = gpr_base.c; @@ -425,10 +448,7 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack) /* Deal with return values that are actually pass-by-reference. */ if (flags & FLAG_RETVAL_REFERENCE) - { - *gpr_base.u++ = (unsigned long) (char *) ecif->rvalue; - intarg_count++; - } + *gpr_base.u++ = (unsigned) (char *) ecif->rvalue; /* Now for the arguments. */ p_argv.v = ecif->avalue; @@ -448,14 +468,11 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack) case FFI_TYPE_LONGDOUBLE: double_tmp = (*p_argv.d)[0]; - if (fparg_count >= NUM_FPR_ARG_REGISTERS - 1) + if (fpr_base.d >= fpr_end.d - 1) { - if (intarg_count >= NUM_GPR_ARG_REGISTERS - && intarg_count % 2 != 0) - { - intarg_count++; - next_arg.u++; - } + fpr_base.d = fpr_end.d; + if (((next_arg.u - stack) & 1) != 0) + next_arg.u += 1; *next_arg.d = double_tmp; next_arg.u += 2; double_tmp = (*p_argv.d)[1]; @@ -468,42 +485,33 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack) double_tmp = (*p_argv.d)[1]; *fpr_base.d++ = double_tmp; } - - fparg_count += 2; FFI_ASSERT (flags & FLAG_FP_ARGUMENTS); break; # endif case FFI_TYPE_DOUBLE: double_tmp = **p_argv.d; - if (fparg_count >= NUM_FPR_ARG_REGISTERS) + if (fpr_base.d >= fpr_end.d) { - if (intarg_count >= NUM_GPR_ARG_REGISTERS - && intarg_count % 2 != 0) - { - intarg_count++; - next_arg.u++; - } + if (((next_arg.u - stack) & 1) != 0) + next_arg.u += 1; *next_arg.d = double_tmp; next_arg.u += 2; } else *fpr_base.d++ = double_tmp; - fparg_count++; FFI_ASSERT (flags & FLAG_FP_ARGUMENTS); break; case FFI_TYPE_FLOAT: double_tmp = **p_argv.f; - if (fparg_count >= NUM_FPR_ARG_REGISTERS) + if (fpr_base.d >= fpr_end.d) { *next_arg.f = (float) double_tmp; next_arg.u += 1; - intarg_count++; } else *fpr_base.d++ = double_tmp; - fparg_count++; FFI_ASSERT (flags & FLAG_FP_ARGUMENTS); break; #endif /* have FPRs */ @@ -513,42 +521,34 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack) is passed in four consecutive GPRs if available. A maximum of 2 long doubles can be passed in gprs. If we do not have 4 GPRs left, the long double is passed on the stack, 4-byte aligned. */ - { - unsigned int int_tmp; - unsigned int ii; - if (intarg_count >= NUM_GPR_ARG_REGISTERS - 3) - { - if (intarg_count < NUM_GPR_ARG_REGISTERS) - intarg_count = NUM_GPR_ARG_REGISTERS; - for (ii = 0; ii < 4; ii++) - { - int_tmp = (*p_argv.ui)[ii]; - *next_arg.u++ = int_tmp; - } - } - else - { - for (ii = 0; ii < 4; ii++) - { - int_tmp = (*p_argv.ui)[ii]; - *gpr_base.u++ = int_tmp; - } - } - intarg_count += 4; - break; - } + if (gpr_base.u >= gpr_end.u - 3) + { + unsigned int ii; + gpr_base.u = gpr_end.u; + for (ii = 0; ii < 4; ii++) + { + unsigned int int_tmp = (*p_argv.ui)[ii]; + *next_arg.u++ = int_tmp; + } + } + else + { + unsigned int ii; + for (ii = 0; ii < 4; ii++) + { + unsigned int int_tmp = (*p_argv.ui)[ii]; + *gpr_base.u++ = int_tmp; + } + } + break; case FFI_TYPE_UINT64: case FFI_TYPE_SINT64: - if (intarg_count == NUM_GPR_ARG_REGISTERS-1) - intarg_count++; - if (intarg_count >= NUM_GPR_ARG_REGISTERS) + if (gpr_base.u >= gpr_end.u - 1) { - if (intarg_count % 2 != 0) - { - intarg_count++; - next_arg.u++; - } + gpr_base.u = gpr_end.u; + if (((next_arg.u - stack) & 1) != 0) + next_arg.u++; *next_arg.ll = **p_argv.ll; next_arg.u += 2; } @@ -559,14 +559,10 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack) (r5,r6), (r7,r8), (r9,r10). If next arg is long long but not correct starting register of pair then skip until the proper starting register. */ - if (intarg_count % 2 != 0) - { - intarg_count ++; - gpr_base.u++; - } + if (((gpr_end.u - gpr_base.u) & 1) != 0) + gpr_base.u++; *gpr_base.ll++ = **p_argv.ll; } - intarg_count += 2; break; case FFI_TYPE_STRUCT: @@ -601,29 +597,22 @@ ffi_prep_args_SYSV (extended_cif *ecif, unsigned *const stack) gprvalue = **p_argv.ui; putgpr: - if (intarg_count >= NUM_GPR_ARG_REGISTERS) + if (gpr_base.u >= gpr_end.u) *next_arg.u++ = gprvalue; else *gpr_base.u++ = gprvalue; - intarg_count++; break; } } /* Check that we didn't overrun the stack... */ FFI_ASSERT (copy_space.c >= next_arg.c); - FFI_ASSERT (gpr_base.u <= stacktop.u - ASM_NEEDS_REGISTERS); - /* The assert below is testing that the number of integer arguments agrees - with the number found in ffi_prep_cif_machdep(). However, intarg_count - is incremented whenever we place an FP arg on the stack, so account for - that before our assert test. */ + FFI_ASSERT (gpr_base.u <= gpr_end.u); #ifndef __NO_FPRS__ - if (fparg_count > NUM_FPR_ARG_REGISTERS) - intarg_count -= fparg_count - NUM_FPR_ARG_REGISTERS; - FFI_ASSERT (fpr_base.u - <= stacktop.u - ASM_NEEDS_REGISTERS - NUM_GPR_ARG_REGISTERS); + FFI_ASSERT (fpr_base.u <= fpr_end.u); #endif - FFI_ASSERT (flags & FLAG_4_GPR_ARGUMENTS || intarg_count <= 4); + FFI_ASSERT (((flags & FLAG_4_GPR_ARGUMENTS) != 0) + == (gpr_end.u - gpr_base.u < 4)); } #define MIN_CACHE_LINE_SIZE 8 -- 2.30.2