[update_mir_test_checks] Add missing MIFlags (#150012)

If the update_mir_test_checks.py script is aware of MIFlags, it can produce
meaningful identifiers in generated FileCheck lines. A few MIFlags that were
introduced more recently have been missing from the script.

Ideally, the MIFlags would be specified in a single place and automatically
made known to the script to avoid this divergence, but for now adding a comment
pointing to the script at the place where the MIFlags are printed seems like a
reasonable trade-off.

This PR only regenerates check lines for a single test as an example of the
effect; other affected tests are not regenerated for now to avoid unnecessary
test churn.

Author: ritter-x2a

llvm/lib/CodeGen/MIRPrinter.cpp

@@ -815,6 +815,9 @@ static void printMI(raw_ostream &OS, MFPrintState &State,
   if (MI.getFlag(MachineInstr::SameSign))
     OS << "samesign ";
 
+  // NOTE: Please add new MIFlags also to the MI_FLAGS_STR in
+  // llvm/utils/update_mir_test_checks.py.
+
   OS << TII->getName(MI.getOpcode());
 
   LS = ListSeparator();

llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-gep-flags.ll

@@ -17,8 +17,8 @@ define i32 @gep_nusw_nuw(ptr %ptr, i32 %idx) {
   ; CHECK-NEXT:   [[MUL1:%[0-9]+]]:_(s64) = G_MUL [[SEXT]], [[C]]
   ; CHECK-NEXT:   [[PTR_ADD1:%[0-9]+]]:_(p0) = G_PTR_ADD [[COPY]], [[MUL1]](s64)
   ; CHECK-NEXT:   [[C1:%[0-9]+]]:_(s64) = G_CONSTANT i64 4
-  ; CHECK-NEXT:   %11:_(p0) = nuw nusw G_PTR_ADD [[PTR_ADD1]], [[C1]](s64)
-  ; CHECK-NEXT:   [[LOAD1:%[0-9]+]]:_(s32) = G_LOAD %11(p0) :: (load (s32) from %ir.gep2)
+  ; CHECK-NEXT:   [[PTR_ADD2:%[0-9]+]]:_(p0) = nuw nusw G_PTR_ADD [[PTR_ADD1]], [[C1]](s64)
+  ; CHECK-NEXT:   [[LOAD1:%[0-9]+]]:_(s32) = G_LOAD [[PTR_ADD2]](p0) :: (load (s32) from %ir.gep2)
   ; CHECK-NEXT:   [[ADD:%[0-9]+]]:_(s32) = G_ADD [[LOAD]], [[LOAD1]]
   ; CHECK-NEXT:   $w0 = COPY [[ADD]](s32)
   ; CHECK-NEXT:   RET_ReallyLR implicit $w0
@@ -77,8 +77,8 @@ define i32 @gep_nusw(ptr %ptr, i32 %idx) {
   ; CHECK-NEXT:   [[MUL1:%[0-9]+]]:_(s64) = G_MUL [[SEXT]], [[C]]
   ; CHECK-NEXT:   [[PTR_ADD1:%[0-9]+]]:_(p0) = G_PTR_ADD [[COPY]], [[MUL1]](s64)
   ; CHECK-NEXT:   [[C1:%[0-9]+]]:_(s64) = G_CONSTANT i64 4
-  ; CHECK-NEXT:   %11:_(p0) = nusw G_PTR_ADD [[PTR_ADD1]], [[C1]](s64)
-  ; CHECK-NEXT:   [[LOAD1:%[0-9]+]]:_(s32) = G_LOAD %11(p0) :: (load (s32) from %ir.gep2)
+  ; CHECK-NEXT:   [[PTR_ADD2:%[0-9]+]]:_(p0) = nusw G_PTR_ADD [[PTR_ADD1]], [[C1]](s64)
+  ; CHECK-NEXT:   [[LOAD1:%[0-9]+]]:_(s32) = G_LOAD [[PTR_ADD2]](p0) :: (load (s32) from %ir.gep2)
   ; CHECK-NEXT:   [[ADD:%[0-9]+]]:_(s32) = G_ADD [[LOAD]], [[LOAD1]]
   ; CHECK-NEXT:   $w0 = COPY [[ADD]](s32)
   ; CHECK-NEXT:   RET_ReallyLR implicit $w0

llvm/utils/update_mir_test_checks.py

@@ -35,9 +35,14 @@
 VREG_RE = re.compile(r"(%[0-9]+)(?:\.[a-z0-9_]+)?(?::[a-z0-9_]+)?(?:\([<>a-z0-9 ]+\))?")
 MI_FLAGS_STR = (
     r"(frame-setup |frame-destroy |nnan |ninf |nsz |arcp |contract |afn "
-    r"|reassoc |nuw |nsw |exact |nofpexcept |nomerge |disjoint )*"
+    r"|reassoc |nuw |nsw |exact |nofpexcept |nomerge |unpredictable "
+    r"|noconvergent |nneg |disjoint |nusw |samesign )*"
 )
 VREG_DEF_FLAGS_STR = r"(?:dead |undef )*"
+
+# Pattern to match the defined vregs and the opcode of an instruction that
+# defines vregs. Opcodes starting with a lower-case 't' are allowed to match
+# ARM's thumb instructions, like tADDi8 and t2ADDri.
 VREG_DEF_RE = re.compile(
     r"^ *(?P<vregs>{2}{0}(?:, {2}{0})*) = "
     r"{1}(?P<opcode>[A-Zt][A-Za-z0-9_]+)".format(