Hi,
This patch fixes an ICE where the compiler crashes (with NEON enabled)
during expansion of an instruction such as:
pr48335-5.c:17:1: error: unrecognizable insn:
}
^
(insn 9 8 10 2 (set (reg:DI 116 [ s ])
(unspec:DI [
(mem/c:DI (plus:SI (reg/f:SI 105 virtual-stack-vars)
(const_int -8 [0xfff8])) [2 S8 A32])
] UNSPEC_MISALIGNED_ACCESS)) pr48335-5.c:15 -1
(nil))
pr48335-5.c:17:1: internal compiler error: in extract_insn, at recog.c:2158
The problem is that generic code (expr.c:expand_expr_real_1, case
VIEW_CONVERT_EXPR) expects to be able to use movmisalign without
explicitly checking that the operands match -- reminiscent of normal
moves, which are generally expected to always work. However, the
current predicates on the NEON movmisalign insn patterns reject MEMs
which refer to virtual registers such as the virtual-stack-vars above,
leading to the ICE, even though the middle end would generally be capable of
rewriting such an instruction into one which is valid.
The fix for this is to tweak the operands for the instruction patterns
in question to allow such virtual registers, pre-reload. This fixes
gcc.dg/pr48335-5.c when the testsuite is run with -march=armv7-a
-mfpu=neon -mfloat-abi=softfp options, with no other changes in
results for gcc, g++ libstdc++.
OK to apply?
Thanks,
Julian
ChangeLog
gcc/
* config/arm/arm.c (neon_vector_mem_operand): Add strict argument.
Permit virtual register pre-reload if !strict.
(coproc_secondary_reload_class): Adjust for neon_vector_mem_operand
change.
* config/arm/arm-protos.h (neon_vector_mem_operand): Adjust
prototype.
* config/arm/neon.md (movmisalignmode): Use
neon_perm_struct_or_reg_operand instead of
neon_struct_or_register_operand.
(*movmisalignmode_neon_load, *movmisalignmode_neon_store): Use
neon_permissive_struct_operand instead of neon_struct_operand.
* config/arm/constraints.md (Un, Um, Us): Adjust calls to
neon_vector_mem_operand.
* config/arm/predicates.md (neon_struct_operand): Adjust call to
neon_vector_mem_operand.
(neon_permissive_struct_operand): New.
(neon_struct_or_register_operand): Rename to...
(neon_perm_struct_or_reg_operand): This. Adjust call to
neon_vector_mem_operand.
Index: gcc/config/arm/arm.c
===
--- gcc/config/arm/arm.c (revision 200070)
+++ gcc/config/arm/arm.c (working copy)
@@ -7863,7 +7863,7 @@ arm_rtx_costs_1 (rtx x, enum rtx_code ou
GET_CODE (SET_SRC (x)) == VEC_SELECT)
{
*total = rtx_cost (SET_DEST (x), code, 0, speed);
- if (!neon_vector_mem_operand (SET_DEST (x), 2))
+ if (!neon_vector_mem_operand (SET_DEST (x), 2, true))
*total += COSTS_N_INSNS (1);
return true;
}
@@ -7874,7 +7874,7 @@ arm_rtx_costs_1 (rtx x, enum rtx_code ou
{
rtx mem = XEXP (XEXP (SET_SRC (x), 0), 0);
*total = rtx_cost (mem, code, 0, speed);
- if (!neon_vector_mem_operand (mem, 2))
+ if (!neon_vector_mem_operand (mem, 2, true))
*total += COSTS_N_INSNS (1);
return true;
}
@@ -10046,7 +10046,7 @@ arm_coproc_mem_operand (rtx op, bool wb)
2 - Element/structure loads (vld1)
*/
int
-neon_vector_mem_operand (rtx op, int type)
+neon_vector_mem_operand (rtx op, int type, bool strict)
{
rtx ind;
@@ -10058,7 +10058,7 @@ neon_vector_mem_operand (rtx op, int typ
|| reg_mentioned_p (virtual_outgoing_args_rtx, op)
|| reg_mentioned_p (virtual_stack_dynamic_rtx, op)
|| reg_mentioned_p (virtual_stack_vars_rtx, op)))
-return FALSE;
+return !strict;
/* Constants are converted into offsets from labels. */
if (!MEM_P (op))
@@ -10168,7 +10168,7 @@ coproc_secondary_reload_class (enum mach
{
if (!TARGET_NEON_FP16)
return GENERAL_REGS;
- if (s_register_operand (x, mode) || neon_vector_mem_operand (x, 2))
+ if (s_register_operand (x, mode) || neon_vector_mem_operand (x, 2, true))
return NO_REGS;
return GENERAL_REGS;
}
Index: gcc/config/arm/arm-protos.h
===
--- gcc/config/arm/arm-protos.h (revision 200070)
+++ gcc/config/arm/arm-protos.h (working copy)
@@ -95,7 +95,7 @@ extern enum reg_class coproc_secondary_r
extern bool arm_tls_referenced_p (rtx);
extern int arm_coproc_mem_operand (rtx, bool);
-extern int neon_vector_mem_operand (rtx, int);
+extern int neon_vector_mem_operand (rtx, int, bool);
extern int neon_struct_mem_operand (rtx);
extern int arm_no_early_store_addr_dep (rtx, rtx);
extern int arm_early_store_addr_dep (rtx, rtx);
Index: gcc/config/arm/neon.md
===
--- gcc/config/arm/neon.md (revision 200070)
+++ gcc/config/arm/neon.md (working copy)
@@ -241,8 +241,8 @@
})
(define_expand movmisalignmode
- [(set (match_operand:VDQX 0 neon_struct_or_register_operand)
- (unspec:VDQX
