x86: honor absolute section when emitting code

Various provisions exist for insns to be placed in the absolute section,
yet actually trying to do so didn't work. While data emission (of non-
zero values) is not allowed by generic code, I think this functionality
is useful for the programmer to be able to determine the size of insns.
Therefore, rather than turning the silnet failure into a verbose one,
make things mostly work; the one class of insns not supported (yet) are
branches (JMP and Jcc) with dynamically determined displacement widths.
In this one case, an error now gets reported instead of silently
ignoring the code.

Also avoid recording ISA / feature usage for insns emitted to the
absolute section.

4 files changed, 100 insertions, 0 deletions

diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index 4fd5a77..f401732 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -139,6 +139,7 @@ if [expr ([istarget "i*86-*-*"] ||  [istarget "x86_64-*-*"]) && [gas_32_check]]
     run_dump_test "noreg32-data16"
     run_list_test "movx16" "-I${srcdir}/$subdir -al"
     run_list_test "movx32" "-al"
+    run_dump_test "sizing32"
     run_dump_test "addr16"
     run_dump_test "addr32"
     run_dump_test "code16"
@@ -1236,5 +1237,9 @@ if [expr ([istarget "i*86-*-*"] || [istarget "x86_64-*-*"]) && [gas_64_check]] t
 
     }
 
+    set ASFLAGS "$old_ASFLAGS --64"
+
+    run_dump_test "sizing64"
+
     set ASFLAGS "$old_ASFLAGS"
 }
diff --git a/gas/testsuite/gas/i386/sizing.s b/gas/testsuite/gas/i386/sizing.s
new file mode 100644
index 0000000..c9b9820
--- /dev/null
+++ b/gas/testsuite/gas/i386/sizing.s
@@ -0,0 +1,55 @@
+	.macro insn, mnem:req, opnds:vararg
+	.struct
+	\mnem	\opnds
+	.equiv	\mnem, .
+	.endm
+
+	insn	inc	%eax
+
+	.equiv .Lis_64bit, inc > 1
+
+	insn	add	$1, %al
+
+	insn	adc	$1, %cl
+
+	insn	sub	$0x12345678, %eax
+
+	insn	sbb	$0x12345678, %ecx
+
+	insn	and	$1, %eax
+
+	insn	call	.
+
+	insn	jecxz	.
+
+	insn	pextrw	$0, %xmm0, %eax
+
+	.macro pextrw_store opnds:vararg
+	{store} pextrw \opnds
+	.endm
+	insn	pextrw_store $0, %xmm0, %eax
+
+	insn	vpextrw	$0, %xmm0, %eax
+
+	.macro vpextrw_evex opnds:vararg
+	{evex} vpextrw \opnds
+	.endm
+	insn	vpextrw_evex $0, %xmm0, %eax
+
+	.if .Lis_64bit
+
+	insn	mov	$0x876543210, %rcx
+
+	insn	movq	0x876543210, %rax
+
+	.else
+
+	insn	lcall	$0, $0
+
+	.code16
+
+	insn	ljmp	$0, $0
+
+	.endif
+
+	insn	bextr	$0x11223344, %fs:(,%eax,2), %eax
diff --git a/gas/testsuite/gas/i386/sizing32.d b/gas/testsuite/gas/i386/sizing32.d
new file mode 100644
index 0000000..3fe8ed8
--- /dev/null
+++ b/gas/testsuite/gas/i386/sizing32.d
@@ -0,0 +1,20 @@
+#name: ix86 insn sizing
+#nm: -B
+#source: sizing.s
+
+#...
+0+03 a adc
+0+02 a add
+0+03 a and
+0+10 a bextr
+0+05 a call
+0+01 a inc
+0+02 a jecxz
+0+07 a lcall
+0+05 a ljmp
+0+05 a pextrw
+0+06 a pextrw_store
+0+06 a sbb
+0+05 a sub
+0+05 a vpextrw
+0+07 a vpextrw_evex
diff --git a/gas/testsuite/gas/i386/sizing64.d b/gas/testsuite/gas/i386/sizing64.d
new file mode 100644
index 0000000..d337885
--- /dev/null
+++ b/gas/testsuite/gas/i386/sizing64.d
@@ -0,0 +1,20 @@
+#name: x86-64 insn sizing
+#nm: -B
+#source: sizing.s
+
+#...
+0+03 a adc
+0+02 a add
+0+03 a and
+0+10 a bextr
+0+05 a call
+0+02 a inc
+0+03 a jecxz
+0+0a a mov
+0+0a a movq
+0+05 a pextrw
+0+06 a pextrw_store
+0+06 a sbb
+0+05 a sub
+0+05 a vpextrw
+0+07 a vpextrw_evex