[lldb] [test/Register] Attempt to fix x86-fp-read.test on Darwin

Darwin seems to use stmmN instead of stN. Use a regex to accept both.

Also try to actually clear st(7).

Differential revision: https://reviews.llvm.org/D88795

Author: mgorny

lldb/test/Shell/Register/Inputs/x86-fp-read.cpp

@@ -14,7 +14,8 @@ int main() {
     {0x8000000000000000, 0x7fff},  // +inf
     {0x8000000000000000, 0xffff},  // -inf
     {0xc000000000000000, 0xffff},  // nan
-    // leave st7 empty to test tag word better
+    // st7 will be freed to test tag word better
+    {0x0000000000000000, 0x0000},  // +0
   };
 
   // unmask divide-by-zero exception
@@ -26,13 +27,16 @@ int main() {
     "finit\n\t"
     "fldcw %1\n\t"
     // load on stack in reverse order to make the result easier to read
+    "fldt 0x70(%0)\n\t"
     "fldt 0x60(%0)\n\t"
     "fldt 0x50(%0)\n\t"
     "fldt 0x40(%0)\n\t"
     "fldt 0x30(%0)\n\t"
     "fldt 0x20(%0)\n\t"
     "fldt 0x10(%0)\n\t"
     "fldt 0x00(%0)\n\t"
+    // free st7
+    "ffree %%st(7)\n\t"
     // this should trigger a divide-by-zero
     "fdivs (%2)\n\t"
     "int3\n\t"

lldb/test/Shell/Register/x86-fp-read.test

@@ -1,5 +1,4 @@
 # XFAIL: system-windows
-# XFAIL: system-darwin
 # REQUIRES: native && (target-x86 || target-x86_64)
 # RUN: %clangxx_host -g %p/Inputs/x86-fp-read.cpp -o %t
 # RUN: %lldb -b -s %s %t | FileCheck %s
@@ -8,20 +7,20 @@ process launch
 
 register read --all
 # CHECK-DAG: fctrl = 0x037b
-# CHECK-DAG: fstat = 0x8884
+# CHECK-DAG: fstat = 0x8084
 # TODO: the following value is incorrect, it's a bug in the way
-# FXSAVE/XSAVE is interpreted; it should be 0xa963 once fixed
-# CHECK-DAG: ftag = 0x00fe
+# FXSAVE/XSAVE is interpreted
+# CHECK-DAG: ftag = 0x007f
 # CHECK-DAG: fop = 0x0033
 
-# CHECK-DAG: st0 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x80 0x00 0x40}
-# CHECK-DAG: st1 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x3f 0x00 0x00}
-# CHECK-DAG: st2 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00}
-# CHECK-DAG: st3 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x80}
-# CHECK-DAG: st4 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x80 0xff 0x7f}
-# CHECK-DAG: st5 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x80 0xff 0xff}
-# CHECK-DAG: st6 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0xc0 0xff 0xff}
-# CHECK-DAG: st7 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00}
+# CHECK-DAG: st{{(mm)?}}0 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x80 0x00 0x40}
+# CHECK-DAG: st{{(mm)?}}1 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x3f 0x00 0x00}
+# CHECK-DAG: st{{(mm)?}}2 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00}
+# CHECK-DAG: st{{(mm)?}}3 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x80}
+# CHECK-DAG: st{{(mm)?}}4 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x80 0xff 0x7f}
+# CHECK-DAG: st{{(mm)?}}5 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x80 0xff 0xff}
+# CHECK-DAG: st{{(mm)?}}6 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0xc0 0xff 0xff}
+# CHECK-DAG: st{{(mm)?}}7 = {0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00}
 
 # fdiv (%rbx) gets encoded into 2 bytes, int3 into 1 byte
 print (void*)($pc-3)