[PATCH] Make hint ranges consistent (Was: For the 16-bit unallocated NOP hints, make disassembly representation consistent with their 32-bit counterparts)

[Artyom Skrobov]

> A1 Hint:
> * Should the hint syntax be conditional as well, to match with the defined
> hint syntaxes? It looks like that whole space is unallocated, so we may as
> well make it available.

The hints did support the conditional syntax from the beginning, although it
was never tested -- not even in my new tests.

These further changes on top of my patch should be sufficient:

diff --git a/test/MC/ARM/basic-arm-instructions.s
b/test/MC/ARM/basic-arm-instructions.s
index 3d2562d..aeec633 100644
--- a/test/MC/ARM/basic-arm-instructions.s
+++ b/test/MC/ARM/basic-arm-instructions.s
@@ -2928,7 +2928,7 @@ Lforward:
         hint #2
         hint #1
         hint #0
-        hint #239
+        hintgt #239
 
 @ CHECK: wfe                            @ encoding: [0x02,0xf0,0x20,0xe3]
 @ CHECK: wfehi                          @ encoding: [0x02,0xf0,0x20,0x83]
@@ -2941,4 +2941,4 @@ Lforward:
 @ CHECK: wfe                            @ encoding: [0x02,0xf0,0x20,0xe3]
 @ CHECK: yield                          @ encoding: [0x01,0xf0,0x20,0xe3]
 @ CHECK: nop                            @ encoding: [0x00,0xf0,0x20,0xe3]
-@ CHECK: hint #239                      @ encoding: [0xef,0xf0,0x20,0xe3]
+@ CHECK: hintgt #239                    @ encoding: [0xef,0xf0,0x20,0xc3]
diff --git a/test/MC/ARM/basic-thumb2-instructions.s
b/test/MC/ARM/basic-thumb2-instructions.s
index ae88d40..fdb2225 100644
--- a/test/MC/ARM/basic-thumb2-instructions.s
+++ b/test/MC/ARM/basic-thumb2-instructions.s
@@ -3603,9 +3603,10 @@ _func:
         hint #1
         hint #0
 
-        hint #15
-        hint #16
-        hint #239
+        itet lt
+        hintlt #15
+        hintge #16
+        hintlt #239
 
 @ CHECK: wfe                            @ encoding: [0x20,0xbf]
 @ CHECK: wfi                            @ encoding: [0x30,0xbf]
@@ -3625,9 +3626,10 @@ _func:
 @ CHECK: yield                          @ encoding: [0x10,0xbf]
 @ CHECK: nop                            @ encoding: [0x00,0xbf]
 
-@ CHECK: hint #15                       @ encoding: [0xf0,0xbf]
-@ CHECK: hint.w #16                     @ encoding: [0xaf,0xf3,0x10,0x80]
-@ CHECK: hint.w #239                    @ encoding: [0xaf,0xf3,0xef,0x80]
+@ CHECK: itet  lt                       @ encoding: [0xb6,0xbf]
+@ CHECK: hintlt #15                     @ encoding: [0xf0,0xbf]
+@ CHECK: hintge.w #16                   @ encoding: [0xaf,0xf3,0x10,0x80]
+@ CHECK: hintlt.w #239                  @ encoding: [0xaf,0xf3,0xef,0x80]
 
 
@---------------------------------------------------------------------------
---
 @ Unallocated wide/narrow hints


> * Why not allow the hint syntax above immediate values of 0xf0? Should the
> DBG instructions not now be re-implemented as hint aliases?

It could be done, but it's hard for me to see any benefit from doing so; and
it would come at the cost of complicating ARMInstPrinter even further.

> T2 Hint
> * Why do we still need the InstAlias for the hint here? Can it not be
> removed like the T1 version?

No, the InstAlias proves necessary for picking up the wide hint when the
value is above #15.