[SystemZ] Fix trap issue and enable expensive checks.

The isBarrier/isTerminator flags have been removed from the SystemZ trap
instructions, so that tests do not fail with EXPENSIVE_CHECKS. This was just
an issue at -O0 and did not affect code output on benchmarks.

(Like Eli pointed out: "targets are split over whether they consider their
"trap" a terminator; x86, AArch64, and NVPTX don't, but ARM, MIPS, PPC, and
SystemZ do. We should probably try to be consistent here.". This is still the
case, although SystemZ has switched sides).

SystemZ now returns true in isMachineVerifierClean() :-)

These Generic tests have been modified so that they can be run with or without
EXPENSIVE_CHECKS: CodeGen/Generic/llc-start-stop.ll and
CodeGen/Generic/print-machineinstrs.ll

Review: Ulrich Weigand, Simon Pilgrim, Eli Friedman
https://bugs.llvm.org/show_bug.cgi?id=33047
https://reviews.llvm.org/D34143

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306106 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/SystemZ/SystemZInstrInfo.td

@@ -189,18 +189,15 @@ let isBranch = 1, isTerminator = 1 in {
 //===----------------------------------------------------------------------===//
 
 // Unconditional trap.
-// FIXME: This trap instruction should be marked as isTerminator, but there is
-// currently a general bug that allows non-terminators to be placed between
-// terminators. Temporarily leave this unmarked until the bug is fixed.
-let isBarrier = 1, hasCtrlDep = 1 in
+let hasCtrlDep = 1 in
   def Trap : Alias<4, (outs), (ins), [(trap)]>;
 
 // Conditional trap.
-let isTerminator = 1, hasCtrlDep = 1, Uses = [CC] in
+let hasCtrlDep = 1, Uses = [CC] in
   def CondTrap : Alias<4, (outs), (ins cond4:$valid, cond4:$R1), []>;
 
 // Fused compare-and-trap instructions.
-let isTerminator = 1, hasCtrlDep = 1 in {
+let hasCtrlDep = 1 in {
   // These patterns work the same way as for compare-and-branch.
   defm CRT   : CmpBranchRRFcPair<"crt",   0xB972, GR32>;
   defm CGRT  : CmpBranchRRFcPair<"cgrt",  0xB960, GR64>;

lib/Target/SystemZ/SystemZTargetMachine.h

@@ -51,8 +51,6 @@ class SystemZTargetMachine : public LLVMTargetMachine {
   }
 
   bool targetSchedulesPostRAScheduling() const override { return true; };
-
-  bool isMachineVerifierClean() const override { return false; }
 };
 
 } // end namespace llvm

test/CodeGen/Generic/llc-start-stop.ll

@@ -1,7 +1,10 @@
-; RUN: llc < %s -debug-pass=Structure -stop-after=loop-reduce -o /dev/null 2>&1 | FileCheck %s -check-prefix=STOP-AFTER
+; Note: -verify-machineinstrs is used in order to make this test compatible with EXPENSIVE_CHECKS.
+; RUN: llc < %s -debug-pass=Structure -stop-after=loop-reduce -verify-machineinstrs -o /dev/null 2>&1 \
+; RUN:   | FileCheck %s -check-prefix=STOP-AFTER
 ; STOP-AFTER: -loop-reduce
 ; STOP-AFTER: Dominator Tree Construction
 ; STOP-AFTER: Loop Strength Reduction
+; STOP-AFTER-NEXT: Verify generated machine code
 ; STOP-AFTER-NEXT: MIR Printing Pass
 
 ; RUN: llc < %s -debug-pass=Structure -stop-before=loop-reduce -o /dev/null 2>&1 | FileCheck %s -check-prefix=STOP-BEFORE

test/CodeGen/Generic/print-machineinstrs.ll

@@ -1,12 +1,25 @@
-; RUN: llc < %s -O3 -debug-pass=Structure -print-machineinstrs=branch-folder -o /dev/null 2>&1 | FileCheck %s
-; RUN: llc < %s -O3 -debug-pass=Structure -print-machineinstrs -o /dev/null 2>&1 | FileCheck %s
-; RUN: llc < %s -O3 -debug-pass=Structure -print-machineinstrs= -o /dev/null 2>&1 | FileCheck %s
+; RUN: llc < %s -O3 -debug-pass=Structure -print-machineinstrs=branch-folder -verify-machineinstrs -o /dev/null 2>&1 \
+; RUN:   | FileCheck %s -check-prefix=PRINT-BRANCH-FOLD
+; RUN: llc < %s -O3 -debug-pass=Structure -print-machineinstrs -verify-machineinstrs -o /dev/null 2>&1 \
+; RUN:   | FileCheck %s -check-prefix=PRINT
+; RUN: llc < %s -O3 -debug-pass=Structure -print-machineinstrs= -verify-machineinstrs -o /dev/null 2>&1 \
+; RUN:   | FileCheck %s -check-prefix=PRINT
+
+; Note: -verify-machineinstrs is used in order to make this test compatible with EXPENSIVE_CHECKS.
 
 define i64 @foo(i64 %a, i64 %b) nounwind {
-; CHECK: -branch-folder  -machineinstr-printer
-; CHECK: Control Flow Optimizer
-; CHECK-NEXT: MachineFunction Printer
-; CHECK: Machine code for function foo:
+; PRINT-BRANCH-FOLD: -branch-folder -machineverifier -machineinstr-printer
+; PRINT-BRANCH-FOLD: Control Flow Optimizer
+; PRINT-BRANCH-FOLD-NEXT: Verify generated machine code
+; PRINT-BRANCH-FOLD-NEXT: MachineFunction Printer
+; PRINT-BRANCH-FOLD: Machine code for function foo:
+
+; PRINT: -branch-folder -machineinstr-printer
+; PRINT: Control Flow Optimizer
+; PRINT-NEXT: MachineFunction Printer
+; PRINT-NEXT: Verify generated machine code
+; PRINT: Machine code for function foo:
+
   %c = add i64 %a, %b
   %d = trunc i64 %c to i32
   %e = zext i32 %d to i64

test/CodeGen/SystemZ/trap-02.ll

@@ -47,9 +47,9 @@ if.end:                                           ; preds = %entry
 define i32 @f3(i32 zeroext %a, i32 *%base, i64 %offset) {
 ; CHECK-LABEL: f3:
 ; CHECK: cl %r2, 0(%r{{[0-5]}},%r3)
+; CHECK: lhi %r2, 0
 ; CHECK-LABEL: .Ltmp0
 ; CHECK: jh .Ltmp0+2
-; CHECK: lhi %r2, 0
 ; CHECK: br %r14
 entry:
   %ptr = getelementptr i32, i32 *%base, i64 %offset
@@ -70,9 +70,9 @@ if.end:                                           ; preds = %entry
 define i64 @f4(i64 %a, i64 *%base, i64 %offset) {
 ; CHECK-LABEL: f4:
 ; CHECK: clg %r2, 0(%r{{[0-5]}},%r3)
+; CHECK: lghi %r2, 0
 ; CHECK-LABEL: .Ltmp1
 ; CHECK: jh .Ltmp1+2
-; CHECK: lghi %r2, 0
 ; CHECK: br %r14
 entry:
   %ptr = getelementptr i64, i64 *%base, i64 %offset