[PATCH] x86-64: always use unsigned 32-bit relocation for 32-bit addressing

[Jan Beulich]

Except for %eip-relative addressing, where we don't have a suitable
relocation type silently wrapping at the 4G boundary, consistently
force use of R_X86_64_32 (in ELF terms) instead of its sign-extending
counterpart. This wasn't right in case there was no base register in
the addressing expression.

Take the opportunity and also remove a redundant piece of code, which
otherwise would need to be adjusted too.

gas/
2017-11-13  Jan Beulich  <jbeulich@suse.com>

	* config/tc-i386.c (build_modrm_byte): Add address override
	prefix checks alongside 64-bit mode ones.
	* testsuite/gas/i386/reloc64.s: Add 32-bit signed/unsigned
	relocation cases.
	* testsuite/gas/i386/reloc64.d: Adjust expectations.

--- 2017-11-10/gas/config/tc-i386.c
+++ 2017-11-10/gas/config/tc-i386.c
@@ -6565,7 +6565,7 @@ build_modrm_byte (void)
 		  i.types[op].bitfield.disp8 = 0;
 		  i.types[op].bitfield.disp16 = 0;
 		  i.types[op].bitfield.disp64 = 0;
-		  if (flag_code != CODE_64BIT)
+		  if (flag_code != CODE_64BIT || i.prefix[ADDR_PREFIX])
 		    {
 		      /* Must be 32 bit */
 		      i.types[op].bitfield.disp32 = 1;
@@ -6590,13 +6590,7 @@ build_modrm_byte (void)
 	    {
 	      i.rm.mode = 0;
 	      if (!i.disp_operands)
-		{
-		  fake_zero_displacement = 1;
-		  /* Instructions with VSIB byte need 32bit displacement
-		     if there is no base register.  */
-		  if (i.tm.opcode_modifier.vecsib)
-		    i.types[op].bitfield.disp32 = 1;
-		}
+		fake_zero_displacement = 1;
 	      if (i.index_reg == 0)
 		{
 		  gas_assert (!i.tm.opcode_modifier.vecsib);
@@ -6641,7 +6635,7 @@ build_modrm_byte (void)
 		  i.types[op].bitfield.disp8 = 0;
 		  i.types[op].bitfield.disp16 = 0;
 		  i.types[op].bitfield.disp64 = 0;
-		  if (flag_code != CODE_64BIT)
+		  if (flag_code != CODE_64BIT || i.prefix[ADDR_PREFIX])
 		    {
 		      /* Must be 32 bit */
 		      i.types[op].bitfield.disp32 = 1;
--- 2017-11-10/gas/testsuite/gas/i386/reloc64.d
+++ 2017-11-10/gas/testsuite/gas/i386/reloc64.d
@@ -51,6 +51,10 @@ Disassembly of section \.text:
 .*[ 	]+R_X86_64_TPOFF32[ 	]+xtrn
 .*[ 	]+R_X86_64_TPOFF32[ 	]+xtrn
 .*[ 	]+R_X86_64_GOTPLT64[ 	]+xtrn
+.*[ 	]+R_X86_64_32S[ 	]+xtrn
+.*[ 	]+R_X86_64_32[ 	]+xtrn
+.*[ 	]+R_X86_64_32S[ 	]+xtrn
+.*[ 	]+R_X86_64_32[ 	]+xtrn
 Disassembly of section \.data:
 #...
 .*[ 	]+R_X86_64_64[ 	]+xtrn
--- 2017-11-10/gas/testsuite/gas/i386/reloc64.s
+++ 2017-11-10/gas/testsuite/gas/i386/reloc64.s
@@ -218,3 +218,9 @@ bad	call	xtrn@gotplt
 bad	.long	xtrn@gotplt
 bad	.word	xtrn@gotplt
 bad	.byte	xtrn@gotplt
+
+	.text
+	mov	xtrn(,%rbx), %eax
+	mov	xtrn(,%ebx), %eax
+	vgatherdps %xmm2, xtrn(,%xmm1), %xmm0
+	addr32 vgatherdps %xmm2, xtrn(,%xmm1), %xmm0