+ /* Calculate the sum of the value stored in the instruction and the
+ addend and check for overflow from the low 16 bits into the high
+ 16 bits. The assembler has already done some of this: If the
+ value stored in the instruction has its 15th bit set, (counting
+ from zero) then the assembler will have added 1 to the value
+ stored in the associated HI16S reloc. So for example, these
+ relocations:
+
+ movhi hi( fred ), r0, r1
+ movea lo( fred ), r1, r1
+
+ will store 0 in the value fields for the MOVHI and MOVEA instructions
+ and addend will be the address of fred, but for these instructions:
+
+ movhi hi( fred + 0x123456), r0, r1
+ movea lo( fred + 0x123456), r1, r1
+
+ the value stored in the MOVHI instruction will be 0x12 and the value
+ stored in the MOVEA instruction will be 0x3456. If however the
+ instructions were:
+
+ movhi hi( fred + 0x10ffff), r0, r1
+ movea lo( fred + 0x10ffff), r1, r1
+
+ then the value stored in the MOVHI instruction would be 0x11 (not
+ 0x10) and the value stored in the MOVEA instruction would be 0xffff.
+ Thus (assuming for the moment that the addend is 0), at run time the
+ MOVHI instruction loads 0x110000 into r1, then the MOVEA instruction
+ adds 0xffffffff (sign extension!) producing 0x10ffff. Similarly if
+ the instructions were:
+
+ movhi hi( fred - 1), r0, r1
+ movea lo( fred - 1), r1, r1
+
+ then 0 is stored in the MOVHI instruction and -1 is stored in the
+ MOVEA instruction.
+
+ Overflow can occur if the addition of the value stored in the
+ instruction plus the addend sets the 15th bit when before it was clear.
+ This is because the 15th bit will be sign extended into the high part,
+ thus reducing its value by one, but since the 15th bit was originally
+ clear, the assembler will not have added 1 to the previous HI16S reloc
+ to compensate for this effect. For example:
+
+ movhi hi( fred + 0x123456), r0, r1
+ movea lo( fred + 0x123456), r1, r1
+
+ The value stored in HI16S reloc is 0x12, the value stored in the LO16
+ reloc is 0x3456. If we assume that the address of fred is 0x00007000
+ then the relocations become:
+
+ HI16S: 0x0012 + (0x00007000 >> 16) = 0x12
+ LO16: 0x3456 + (0x00007000 & 0xffff) = 0xa456
+
+ but when the instructions are executed, the MOVEA instruction's value
+ is signed extended, so the sum becomes:
+
+ 0x00120000
+ + 0xffffa456
+ ------------
+ 0x0011a456 but 'fred + 0x123456' = 0x0012a456
+
+ Note that if the 15th bit was set in the value stored in the LO16
+ reloc, then we do not have to do anything:
+
+ movhi hi( fred + 0x10ffff), r0, r1
+ movea lo( fred + 0x10ffff), r1, r1
+
+ HI16S: 0x0011 + (0x00007000 >> 16) = 0x11
+ LO16: 0xffff + (0x00007000 & 0xffff) = 0x6fff
+
+ 0x00110000
+ + 0x00006fff
+ ------------
+ 0x00116fff = fred + 0x10ffff = 0x7000 + 0x10ffff
+
+ Overflow can also occur if the computation carries into the 16th bit
+ and it also results in the 15th bit having the same value as the 15th
+ bit of the original value. What happens is that the HI16S reloc
+ will have already examined the 15th bit of the original value and
+ added 1 to the high part if the bit is set. This compensates for the
+ sign extension of 15th bit of the result of the computation. But now
+ there is a carry into the 16th bit, and this has not been allowed for.
+
+ So, for example if fred is at address 0xf000:
+
+ movhi hi( fred + 0xffff), r0, r1 [bit 15 of the offset is set]
+ movea lo( fred + 0xffff), r1, r1
+
+ HI16S: 0x0001 + (0x0000f000 >> 16) = 0x0001
+ LO16: 0xffff + (0x0000f000 & 0xffff) = 0xefff (carry into bit 16 is lost)
+
+ 0x00010000
+ + 0xffffefff
+ ------------
+ 0x0000efff but 'fred + 0xffff' = 0x0001efff
+
+ Similarly, if the 15th bit remains clear, but overflow occurs into
+ the 16th bit then (assuming the address of fred is 0xf000):
+
+ movhi hi( fred + 0x7000), r0, r1 [bit 15 of the offset is clear]
+ movea lo( fred + 0x7000), r1, r1
+
+ HI16S: 0x0000 + (0x0000f000 >> 16) = 0x0000
+ LO16: 0x7000 + (0x0000f000 & 0xffff) = 0x6fff (carry into bit 16 is lost)
+
+ 0x00000000
+ + 0x00006fff
+ ------------
+ 0x00006fff but 'fred + 0x7000' = 0x00016fff
+
+ Note - there is no need to change anything if a carry occurs, and the
+ 15th bit changes its value from being set to being clear, as the HI16S
+ reloc will have already added in 1 to the high part for us:
+
+ movhi hi( fred + 0xffff), r0, r1 [bit 15 of the offset is set]
+ movea lo( fred + 0xffff), r1, r1
+
+ HI16S: 0x0001 + (0x00007000 >> 16)
+ LO16: 0xffff + (0x00007000 & 0xffff) = 0x6fff (carry into bit 16 is lost)
+
+ 0x00010000
+ + 0x00006fff (bit 15 not set, so the top half is zero)
+ ------------
+ 0x00016fff which is right (assuming that fred is at 0x7000)
+
+ but if the 15th bit goes from being clear to being set, then we must
+ once again handle overflow:
+
+ movhi hi( fred + 0x7000), r0, r1 [bit 15 of the offset is clear]
+ movea lo( fred + 0x7000), r1, r1
+
+ HI16S: 0x0000 + (0x0000ffff >> 16)
+ LO16: 0x7000 + (0x0000ffff & 0xffff) = 0x6fff (carry into bit 16)
+
+ 0x00000000
+ + 0x00006fff (bit 15 not set, so the top half is zero)
+ ------------
+ 0x00006fff which is wrong (assuming that fred is at 0xffff)
+ */
+
+ {
+ long result;
+
+ insn = bfd_get_16 (abfd, address);
+ result = insn + addend;
+
+#define BIT15_SET(x) ((x) & 0x8000)
+#define OVERFLOWS(a,i) ((((a) & 0xffff) + (i)) > 0xffff)
+
+ if ((BIT15_SET (result) && ! BIT15_SET (addend))
+ || (OVERFLOWS (addend, insn)
+ && ((! BIT15_SET (insn)) || (BIT15_SET (addend)))))
+ {
+ boolean already_updated;
+ bfd_byte * hi16s_address = find_remembered_hi16s_reloc
+ (addend, & already_updated);
+
+ /* Amend the matching HI16_S relocation. */
+ if (hi16s_address != NULL)
+ {
+ if (! already_updated)
+ {
+ insn = bfd_get_16 (abfd, hi16s_address);
+ insn += 1;
+ bfd_put_16 (abfd, insn, hi16s_address);
+ }
+ }
+ else
+ {
+ fprintf (stderr, _("FAILED to find previous HI16 reloc\n"));
+ return bfd_reloc_overflow;
+ }
+ }
+
+ /* Do not complain if value has top bit set, as this has been anticipated. */
+ insn = result & 0xffff;
+ break;
+ }
+
+ case R_V850_8:
+ addend += (char) bfd_get_8 (abfd, address);
+
+ saddend = (bfd_signed_vma) addend;
+
+ if (saddend > 0x7f || saddend < -0x80)
+ return bfd_reloc_overflow;
+
+ bfd_put_8 (abfd, addend, address);
+ return bfd_reloc_ok;
+
+ case R_V850_CALLT_16_16_OFFSET:
+ addend += bfd_get_16 (abfd, address);
+
+ saddend = (bfd_signed_vma) addend;
+
+ if (saddend > 0xffff || saddend < 0)
+ return bfd_reloc_overflow;
+