[binutils-gdb] Aligned vs. unaligned ppc32 relocs

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=63f6e94fb3cc5b6a2cfb8c28686f150e7226ab7e

commit 63f6e94fb3cc5b6a2cfb8c28686f150e7226ab7e
Author: Alan Modra <amodra@gmail.com>
Date:   Wed Aug 14 16:31:05 2019 +0930

    Aligned vs. unaligned ppc32 relocs
    
    Given R_PPC_ADDR32 or R_PPC_UADDR32 relocs, this patch generates
    R_PPC_ADDR32 or R_PPC_UADDR32 dynamic relocs from either type
    depending on whether r_offset is 4-byte aligned, and similarly for
    R_PPC_ADDR16/R_PPC_UADDR16.
    
    	* elf32-ppc.c (ppc_elf_relocate_section): Optimize unaligned relocs.

Diff:
---
 bfd/ChangeLog   | 4 ++++
 bfd/elf32-ppc.c | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 8e63c9b..5c3efb9 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,7 @@
+2019-08-16  Alan Modra  <amodra@gmail.com>
+
+	* elf32-ppc.c (ppc_elf_relocate_section): Optimize unaligned relocs.
+
 2019-08-15  Jim Wilson  <jimw@sifive.com>
 
 	* elfnn-riscv.c (perform_relocation) <R_RISCV_RVC_LUI>: If
diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c
index e683590..78d39ef 100644
--- a/bfd/elf32-ppc.c
+++ b/bfd/elf32-ppc.c
@@ -8157,6 +8157,14 @@ ppc_elf_relocate_section (bfd *output_bfd,
 	      outrel.r_offset += (input_section->output_section->vma
 				  + input_section->output_offset);
 
+	      /* Optimize unaligned reloc use.  */
+	      if ((r_type == R_PPC_ADDR32 && (outrel.r_offset & 3) != 0)
+		  || (r_type == R_PPC_UADDR32 && (outrel.r_offset & 3) == 0))
+		r_type ^= R_PPC_ADDR32 ^ R_PPC_UADDR32;
+	      if ((r_type == R_PPC_ADDR16 && (outrel.r_offset & 1) != 0)
+		  || (r_type == R_PPC_UADDR16 && (outrel.r_offset & 1) == 0))
+		r_type ^= R_PPC_ADDR16 ^ R_PPC_UADDR16;
+
 	      if (skip)
 		memset (&outrel, 0, sizeof outrel);
 	      else if (!SYMBOL_REFERENCES_LOCAL (info, h))