From: Jan Beulich <jbeulich@suse.com>
Date: Mon, 4 Jul 2022 06:31:21 +0000 (+0200)
Subject: x86-64: improve handling of branches to absolute addresses
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=9386188e95f4dee6319c51b30e2ea64b27ae0084;p=binutils-gdb.git

x86-64: improve handling of branches to absolute addresses

There are two related problems here: The use of "addr32" on a direct
branch would, besides causing a warning, result in operands to be
permitted which mistakenly are refused without "addr32". Plus at some
point not too long ago I'm afraid it may have been me who regressed the
relocation addends emitted for such branches. Correct both problems,
adding a testcase to guard against regressing this again.
---

diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 5d486570bf8..8b245cc4d34 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -4975,7 +4975,9 @@ md_assemble (char *line)
   if (i.imm_operands)
     optimize_imm ();
 
-  if (i.disp_operands && !want_disp32 (current_templates->start))
+  if (i.disp_operands && !want_disp32 (current_templates->start)
+      && (!current_templates->start->opcode_modifier.jump
+	  || i.jumpabsolute || i.types[0].bitfield.baseindex))
     {
       for (j = 0; j < i.operands; ++j)
 	{
@@ -5985,7 +5987,9 @@ optimize_disp (void)
 	    /* Optimize 64-bit displacement to 32-bit for 64-bit BFD.  */
 	    if ((i.types[op].bitfield.disp32
 		 || (flag_code == CODE_64BIT
-		     && want_disp32 (current_templates->start)))
+		     && want_disp32 (current_templates->start)
+		     && (!current_templates->start->opcode_modifier.jump
+			 || i.jumpabsolute || i.types[op].bitfield.baseindex)))
 		&& fits_in_unsigned_long (op_disp))
 	      {
 		/* If this operand is at most 32 bits, convert
diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index a4fc5b4096b..ebb1b492462 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -1314,6 +1314,7 @@ if [gas_64_check] then {
 	run_dump_test "x86-64-branch-3"
 	run_list_test "x86-64-branch-4" "-al -mintel64"
 	run_list_test "x86-64-branch-5" "-al"
+	run_dump_test "x86-64-branch-6"
 
 	run_dump_test "x86-64-rip-2"
 
diff --git a/gas/testsuite/gas/i386/x86-64-branch-6.d b/gas/testsuite/gas/i386/x86-64-branch-6.d
new file mode 100644
index 00000000000..a2d388f1277
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-branch-6.d
@@ -0,0 +1,21 @@
+#objdump: -r
+#name: x86-64 branch 6
+#warning_output: x86-64-branch-6.e
+
+.*: +file format .*
+
+RELOCATION RECORDS FOR \[\.text\]:
+OFFSET +TYPE +VALUE *
+0+01 R_X86_64_PC32 +\*ABS\*\+0x000000008765431d
+0+11 R_X86_64_PC32 +\*ABS\*\+0x000000087654320c
+0+21 R_X86_64_PC32 +\*ABS\*\+0x000000008765431d
+0+31 R_X86_64_PC32 +\*ABS\*\+0x000000087654320c
+0+07 R_X86_64_PC32 +\*ABS\*\+0x000000008765431d
+0+0c R_X86_64_PC32 +\*ABS\*\+0x000000008765431d
+0+17 R_X86_64_PC32 +\*ABS\*\+0x000000087654320c
+0+1c R_X86_64_PC32 +\*ABS\*\+0x000000087654320c
+0+27 R_X86_64_PC32 +\*ABS\*\+0x000000008765431d
+0+2c R_X86_64_PC32 +\*ABS\*\+0x000000008765431d
+0+37 R_X86_64_PC32 +\*ABS\*\+0x000000087654320c
+0+3c R_X86_64_PC32 +\*ABS\*\+0x000000087654320c
+#pass
diff --git a/gas/testsuite/gas/i386/x86-64-branch-6.e b/gas/testsuite/gas/i386/x86-64-branch-6.e
new file mode 100644
index 00000000000..1dc58ea11cb
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-branch-6.e
@@ -0,0 +1,7 @@
+.*: Assembler messages:
+.*:12: Warning: skipping prefixes on `call'
+.*:13: Warning: skipping prefixes on `je'
+.*:14: Warning: skipping prefixes on `jmp'
+.*:16: Warning: skipping prefixes on `call'
+.*:17: Warning: skipping prefixes on `je'
+.*:18: Warning: skipping prefixes on `jmp'
diff --git a/gas/testsuite/gas/i386/x86-64-branch-6.s b/gas/testsuite/gas/i386/x86-64-branch-6.s
new file mode 100644
index 00000000000..a5b108e5abf
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-branch-6.s
@@ -0,0 +1,18 @@
+	.text
+
+branch_6:
+	call	0x87654321
+	je	0x87654321
+	jmp	0x87654321
+
+	call	0x876543210
+	je	0x876543210
+	jmp	0x876543210
+
+	addr32 call	0x87654321
+	addr32 je	0x87654321
+	addr32 jmp	0x87654321
+
+	addr32 call	0x876543210
+	addr32 je	0x876543210
+	addr32 jmp	0x876543210