Subzero: Update tests and build scripts for sandboxing.

Makefile.standalone

@@ -146,7 +146,7 @@ UNITTEST_OBJS = $(patsubst %.cpp, $(OBJDIR)/unittest/%.o, $(UNITTEST_SRCS))
 UNITTEST_LIB_OBJS = $(filter-out $(OBJDIR)/llvm2ice.o,$(OBJS))
 
 # Keep all the first target so it's the default.
-all: $(OBJDIR)/llvm2ice make_symlink
+all: $(OBJDIR)/llvm2ice make_symlink runtime
 
 # Creates symbolic link so that testing is easier. Also runs
 # llvm2ice to verify that the defines flags have valid values,
@@ -157,10 +157,8 @@ make_symlink: $(OBJDIR)/llvm2ice
 	@echo "Build Attributes:"
 	@$(OBJDIR)/llvm2ice --build-atts
 
-.PHONY: all make_symlink bloat
+.PHONY: all make_symlink runtime bloat
 
-# TODO(kschimpf): Fix python scripts to directly get build attributes
-# rather than generating $(OBJDIR)/llvm2ice.build_atts.
 $(OBJDIR)/llvm2ice: $(OBJS)
 	$(CXX) $(LDFLAGS) -o $@ $^ $(LLVM_LDFLAGS) \
                -Wl,-rpath=$(abspath $(LIBCXX_INSTALL_PATH)/lib)
@@ -191,6 +189,19 @@ $(OBJDIR):
 $(OBJDIR)/unittest: $(OBJDIR)
 	@mkdir -p $@
 
+RT_SRC := runtime/szrt.c runtime/szrt_ll.ll
+RT_OBJ := build/runtime/szrt_native_x8632.o build/runtime/szrt_sb_x8632.o
+
+runtime: $(RT_OBJ)
+
+# Use runtime.is.built so that build-runtime.py is invoked only once
+# even in a parallel build.
+.INTERMEDIATE: runtime.is.built
+$(RT_OBJ): runtime.is.built
+runtime.is.built: $(RT_SRC)
+	@echo ================ Building Subzero runtime ================
+	./pydir/build-runtime.py -v
+
 check-lit: $(OBJDIR)/llvm2ice make_symlink
 	LLVM_BIN_PATH=$(LLVM_BIN_PATH) \
 	BINUTILS_BIN_PATH=$(BINUTILS_BIN_PATH) \
@@ -200,10 +211,10 @@ check-unit: $(OBJDIR)/run_unittests
 	$(OBJDIR)/run_unittests
 
 ifdef MINIMAL
-check: check-lit check-unit
+check: check-lit check-unit runtime
 	@echo "Crosstests ignored, minimal build"
 else
-check: check-lit check-unit
+check: check-lit check-unit runtime
 	(cd crosstest; ./runtests.sh)
 endif
 

pydir/build-runtime.py

+#!/usr/bin/env python2
+
+import argparse
+import os
+import shutil
+import tempfile
+from utils import shellcmd
+from utils import FindBaseNaCl
+
+def Translate(ll_files, extra_args, obj, verbose):
+    """Translate a set of input bitcode files into a single object file.
+
+    Use pnacl-llc to translate textual bitcode input ll_files into object file
+    obj, using extra_args as the architectural flags.
+    """
+    shellcmd(['cat'] + ll_files + ['|',
+              'pnacl-llc',
+              '-externalize',
+              '-filetype=obj',
+              '-bitcode-format=llvm',
+              '-o', obj
+          ] + extra_args, echo=verbose)
+    shellcmd(['objcopy',
+              '--localize-symbol=nacl_tp_tdb_offset',
+              '--localize-symbol=nacl_tp_tls_offset',
+              obj
+        ], echo=verbose)
+
+def main():
+    """Build the Subzero runtime support library for all architectures.
+    """
+    argparser = argparse.ArgumentParser(
+        description='    ' + main.__doc__,
+        formatter_class=argparse.RawTextHelpFormatter)
+    argparser.add_argument('--verbose', '-v', dest='verbose',
+                           action='store_true',
+                           help='Display some extra debugging output')
+    args = argparser.parse_args()
+    nacl_root = FindBaseNaCl()
+    os.environ['PATH'] = (
+        '{root}/toolchain/linux_x86/pnacl_newlib/bin{sep}' +
+        '{path}'
+        ).format(root=nacl_root, sep=os.pathsep, path=os.environ['PATH'])
+    srcdir = (
+        '{root}/toolchain_build/src/subzero/runtime'
+        ).format(root=nacl_root)
+    rtdir = (
+        '{root}/toolchain_build/src/subzero/build/runtime'
+        ).format(root=nacl_root)
+    try:
+        tempdir = tempfile.mkdtemp()
+        if os.path.exists(rtdir) and not os.path.isdir(rtdir):
+            os.remove(rtdir)
+        if not os.path.exists(rtdir):
+            os.makedirs(rtdir)
+        # Compile srcdir/szrt.c to tempdir/szrt.ll
+        shellcmd(['pnacl-clang',
+                  '-O2',
+                  '-c',
+                  '{srcdir}/szrt.c'.format(srcdir=srcdir),
+                  '-o', '{dir}/szrt.tmp.bc'.format(dir=tempdir)
+            ], echo=args.verbose)
+        shellcmd(['pnacl-opt',
+                  '-pnacl-abi-simplify-preopt',
+                  '-pnacl-abi-simplify-postopt',
+                  '-pnaclabi-allow-debug-metadata',
+                  '{dir}/szrt.tmp.bc'.format(dir=tempdir),
+                  '-S',
+                  '-o', '{dir}/szrt.ll'.format(dir=tempdir)
+            ], echo=args.verbose)
+        ll_files = ['{dir}/szrt.ll'.format(dir=tempdir),
+                    '{srcdir}/szrt_ll.ll'.format(srcdir=srcdir)]
+        # Translate tempdir/szrt.ll and srcdir/szrt_ll.ll to szrt_native_x8632.o
+        Translate(ll_files,
+                  ['-mtriple=i386-unknown-linux-gnu', '-mcpu=pentium4m'],
+                  '{rtdir}/szrt_native_x8632.o'.format(rtdir=rtdir),
+                  args.verbose)
+        # Translate tempdir/szrt.ll and srcdir/szrt_ll.ll to szrt_sb_x8632.o
+        Translate(ll_files,
+                  ['-mtriple=i686-none-nacl-gnu', '-mcpu=pentium4m'],
+                  '{rtdir}/szrt_sb_x8632.o'.format(rtdir=rtdir),
+                  args.verbose)
+    finally:
+        try:
+            shutil.rmtree(tempdir)
+        except OSError as exc:
+            if exc.errno != errno.ENOENT: # ENOENT - no such file or directory
+                raise # re-raise exception
+
+if __name__ == '__main__':
+    main()

pydir/crosstest.py

@@ -24,8 +24,8 @@ if __name__ == '__main__':
     that calls the test functions with a variety of interesting inputs
     and compares their results.
     """
-    # arch_map maps a Subzero target string to an llvm-mc -arch string.
-    arch_map = { 'x8632':'x86', 'x8664':'x86-64', 'arm':'arm' }
+    # arch_map maps a Subzero target string to an llvm-mc -triple string.
+    arch_map = { 'x8632':'i686', 'x8664':'x86_64', 'arm':'armv7a' }
     desc = 'Build a cross-test that compares Subzero and llc translation.'
     argparser = argparse.ArgumentParser(description=desc)
     argparser.add_argument('--test', required=True, action='append',
@@ -113,7 +113,7 @@ if __name__ == '__main__':
                   bitcode])
         if args.filetype != 'obj':
             shellcmd(['llvm-mc',
-                      '-arch=' + arch_map[args.target],
+                      '-triple=' + arch_map[args.target],
                       '-filetype=obj',
                       '-o=' + obj_sz,
                       asm_sz])
@@ -144,12 +144,9 @@ if __name__ == '__main__':
         else:
             objs.append(bitcode)
 
-    # Use 'clang szrt.c'  -or-  'clang++ szrt.cpp'
     objs.append((
-            '{root}/toolchain_build/src/subzero/runtime/szrt.{ext}'
-            ).format(root=nacl_root, ext='c' if pure_c else 'cpp'))
-    objs.append((
-            '{root}/toolchain_build/src/subzero/runtime/szrt_i686.ll'
+            '{root}/toolchain_build/src/subzero/build/runtime/' +
+            'szrt_native_x8632.o'
             ).format(root=nacl_root))
     linker = 'clang' if pure_c else 'clang++'
     shellcmd([linker, '-g', '-m32', args.driver] +

pydir/szbuild.py

@@ -83,6 +83,8 @@ def AddOptionalArgs(argparser):
     argparser.add_argument('--filetype', default='iasm', dest='filetype',
                            choices=['obj', 'asm', 'iasm'],
                            help='Output file type.  Default %(default)s.')
+    argparser.add_argument('--sandbox', dest='sandbox', action='store_true',
+                           help='Enabled sandboxing in the translator')
     argparser.add_argument('--verbose', '-v', dest='verbose',
                            action='store_true',
                            help='Display some extra debugging output')
@@ -150,10 +152,12 @@ def ProcessPexe(args, pexe, exe):
     pexe = pipes.quote(pexe)
 
     nacl_root = FindBaseNaCl()
+    path_addition = (
+        '{root}/toolchain/linux_x86/pnacl_newlib/bin'
+        ).format(root=nacl_root)
     os.environ['PATH'] = (
-        '{root}/toolchain/linux_x86/pnacl_newlib/bin{sep}' +
-        '{path}'
-        ).format(root=nacl_root, sep=os.pathsep, path=os.environ['PATH'])
+        '{dir}{sep}{path}'
+        ).format(dir=path_addition, sep=os.pathsep, path=os.environ['PATH'])
     obj_llc = pexe_base + '.llc.o'
     obj_sz = pexe_base + '.sz.o'
     asm_sz = pexe_base + '.sz.s'
@@ -168,9 +172,8 @@ def ProcessPexe(args, pexe, exe):
     llvm2ice = (
         '{root}/toolchain_build/src/subzero/llvm2ice'
         ).format(root=nacl_root)
-    llcbin = (
-        '{root}/toolchain/linux_x86/pnacl_newlib/bin/llc'
-        ).format(root=nacl_root)
+    llcbin = 'llc'
+    gold = 'le32-nacl-ld.gold'
     opt_level = args.optlevel
     opt_level_map = { 'm1':'0', '-1':'0', '0':'0', '1':'1', '2':'2' }
     hybrid = args.include or args.exclude
@@ -180,19 +183,22 @@ def ProcessPexe(args, pexe, exe):
                    NewerThanOrNotThere(llcbin, obj_llc)):
         # Only run pnacl-translate in hybrid mode.
         shellcmd(['pnacl-translate',
+                  '-split-module=1',
                   '-ffunction-sections',
                   '-fdata-sections',
                   '-c',
-                  '-arch', 'x86-32-linux',
+                  '-arch', 'x86-32' if args.sandbox else 'x86-32-linux',
                   '-O' + opt_level_map[opt_level],
                   '--pnacl-driver-append-LLC_FLAGS_EXTRA=-externalize',
                   '-o', obj_llc] +
+                 (['--pnacl-driver-verbose'] if args.verbose else []) +
                  args.llc_args +
                  [pexe],
                  echo=args.verbose)
-        shellcmd((
-            'objcopy --redefine-sym _start=_user_start {obj}'
-            ).format(obj=obj_llc), echo=args.verbose)
+        if not args.sandbox:
+            shellcmd((
+                'objcopy --redefine-sym _start=_user_start {obj}'
+                ).format(obj=obj_llc), echo=args.verbose)
         # Generate llc syms file for consistency, even though it's not used.
         shellcmd((
             'nm {obj} | sed -n "s/.* [a-zA-Z] //p" > {sym}'
@@ -210,16 +216,20 @@ def ProcessPexe(args, pexe, exe):
                  (['-externalize',
                    '-ffunction-sections',
                    '-fdata-sections'] if hybrid else []) +
+                 (['-sandbox'] if args.sandbox else []) +
                  args.sz_args +
                  [pexe],
                  echo=args.verbose)
         if args.filetype != 'obj':
             shellcmd((
-                'llvm-mc -arch=x86 -filetype=obj -o {obj} {asm}'
-                ).format(asm=asm_sz, obj=obj_sz), echo=args.verbose)
-        shellcmd((
-            'objcopy --redefine-sym _start=_user_start {obj}'
-            ).format(obj=obj_sz), echo=args.verbose)
+                'llvm-mc -triple={triple} -filetype=obj -o {obj} {asm}'
+                ).format(asm=asm_sz, obj=obj_sz,
+                         triple='i686-nacl' if args.sandbox else 'i686'),
+                     echo=args.verbose)
+        if not args.sandbox:
+            shellcmd((
+                'objcopy --redefine-sym _start=_user_start {obj}'
+                ).format(obj=obj_sz), echo=args.verbose)
         if hybrid:
             shellcmd((
                 'nm {obj} | sed -n "s/.* [a-zA-Z] //p" > {sym}'
@@ -266,29 +276,46 @@ def ProcessPexe(args, pexe, exe):
             'objcopy -w --localize-symbol="*" {partial}'
             ).format(partial=obj_partial), echo=args.verbose)
         shellcmd((
-            'objcopy --globalize-symbol=_user_start {partial}'
-            ).format(partial=obj_partial), echo=args.verbose)
+            'objcopy --globalize-symbol={start} {partial}'
+            ).format(partial=obj_partial,
+                     start='_start' if args.sandbox else '_user_start'),
+                 echo=args.verbose)
 
     # Run the linker regardless of hybrid mode.
     linker = (
         '{root}/../third_party/llvm-build/Release+Asserts/bin/clang'
         ).format(root=nacl_root)
-    shellcmd((
-        '{ld} -m32 {partial} -o {exe} -O{opt_level} ' +
-        # Keep the rest of this command line (except szrt.c) in sync
-        # with RunHostLD() in pnacl-translate.py.
-        '{root}/toolchain/linux_x86/pnacl_newlib/translator/x86-32-linux/lib/' +
-        '{{unsandboxed_irt,irt_random,irt_query_list}}.o ' +
-        '{root}/toolchain_build/src/subzero/runtime/szrt.c ' +
-        '{root}/toolchain_build/src/subzero/runtime/szrt_i686.ll ' +
-        '-lpthread -lrt'
-        ).format(ld=linker, partial=obj_partial, exe=exe,
-                 opt_level=opt_level_map[opt_level], root=nacl_root),
-             echo=args.verbose)
+    if args.sandbox:
+        linklib = ('{root}/toolchain/linux_x86/pnacl_newlib/translator/' +
+                   'x86-32/lib').format(root=nacl_root)
+        shellcmd((
+            '{gold} -nostdlib --no-fix-cortex-a8 --eh-frame-hdr -z text ' +
+            '--build-id --entry=__pnacl_start -static ' +
+            '{linklib}/crtbegin.o {partial} ' +
+            '{root}/toolchain_build/src/subzero/build/runtime/' +
+            'szrt_sb_x8632.o ' +
+            '{linklib}/libpnacl_irt_shim_dummy.a --start-group ' +
+            '{linklib}/libgcc.a {linklib}/libcrt_platform.a ' +
+            '--end-group {linklib}/crtend.o --undefined=_start ' +
+            '-o {exe}'
+            ).format(gold=gold, linklib=linklib, partial=obj_partial, exe=exe,
+                     root=nacl_root),
+                 echo=args.verbose)
+    else:
+        shellcmd((
+            '{ld} -m32 {partial} -o {exe} ' +
+            # Keep the rest of this command line (except szrt_native_x8632.o) in
+            # sync with RunHostLD() in pnacl-translate.py.
+            '{root}/toolchain/linux_x86/pnacl_newlib/translator/x86-32-linux/' +
+            'lib/{{unsandboxed_irt,irt_random,irt_query_list}}.o ' +
+            '{root}/toolchain_build/src/subzero/build/runtime/' +
+            'szrt_native_x8632.o -lpthread -lrt'
+            ).format(ld=linker, partial=obj_partial, exe=exe, root=nacl_root),
+                 echo=args.verbose)
 
     # Put the extra verbose printing at the end.
     if args.verbose:
-        print 'PATH={path}'.format(path=os.environ['PATH'])
+        print 'PATH: {path}'.format(path=path_addition)
         if hybrid:
             print 'include={regex}'.format(regex=re_include_str)
             print 'exclude={regex}'.format(regex=re_exclude_str)

pydir/szbuild_spec2k.py

@@ -14,6 +14,8 @@ def main():
     Afterwards, the executables can be run from the
     native_client/tests/spec2k/ directory as:
     './run_all.sh RunBenchmarks SetupGccX8632Opt {train|ref} ...'
+    -- or --
+    './run_all.sh RunBenchmarks SetupPnaclX8632Opt {train|ref} ...'
     """
     nacl_root = FindBaseNaCl()
     # Use the same default ordering as spec2k/run_all.sh.
@@ -31,6 +33,7 @@ def main():
         print 'Unknown component{s}: '.format(s='s' if len(bad) > 1 else '') + \
             ' '.join(x for x in bad)
         sys.exit(1)
+    suffix = 'pnacl.opt.x8632' if args.sandbox else 'gcc.opt.x8632'
     for comp in args.comps:
         name = os.path.splitext(comp)[1] or comp
         if name[0] == '.':
@@ -40,8 +43,9 @@ def main():
                              '{name}.opt.stripped.pexe'
                              ).format(root=nacl_root, comp=comp, name=name),
                             ('{root}/tests/spec2k/{comp}/' +
-                             '{name}.gcc.opt.x8632'
-                             ).format(root=nacl_root, comp=comp, name=name))
+                             '{name}.{suffix}'
+                             ).format(root=nacl_root, comp=comp, name=name,
+                                      suffix=suffix))
 
 if __name__ == '__main__':
     main()

runtime/szrt.c

@@ -7,17 +7,37 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This file implements the runtime helper routines that are needed by
-// Subzero.  This needs to be compiled by some non-Subzero compiler.
+// This file implements wrappers for particular bitcode instructions
+// that are too uncommon and complex for a particular target to bother
+// implementing directly in Subzero target lowering.  This needs to be
+// compiled by some non-Subzero compiler.
 //
 //===----------------------------------------------------------------------===//
 
 #include <stdint.h>
 #include <stdlib.h>
 
-uint32_t cvtftoui32(float value) { return (uint32_t)value; }
+// TODO(stichnot): The various NaN cross tests try to map Subzero's
+// undefined behavior to the same as llc's undefined behavior, as
+// observed by the cross tests.  This will have to be kept up to date
+// with any future changes to llc, and may also have to be different
+// for different targets.  It would be better to find a more
+// appropriate set of llc options when building the Subzero runtime.
+//
+// We test for NaN using "value==value" instead of using isnan(value)
+// to avoid an external dependency on fpclassify().
+
+uint32_t cvtftoui32(float value) {
+  if (value == value) // NaNaN
+    return (uint32_t)value;
+  return 0x80000000;
+}
 
-uint32_t cvtdtoui32(double value) { return (uint32_t)value; }
+uint32_t cvtdtoui32(double value) {
+  if (value == value) // NaNaN
+    return (uint32_t)value;
+  return 0x80000000;
+}
 
 int64_t cvtftosi64(float value) { return (int64_t)value; }
 

runtime/szrt.cpp

-//===- subzero/runtime/szrt.cpp - Subzero runtime source ------------------===//
-//
-//                        The Subzero Code Generator
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file is a C++ wrapper to szrt.c since clang++ complains about
-// .c files.
-//
-//===----------------------------------------------------------------------===//
-
-extern "C" {
-#include "szrt.c"
-}

runtime/szrt_i686.ll → runtime/szrt_ll.ll

-target triple = "i386-unknown-linux-gnu"
+;;===- subzero/runtime/szrt_ll.ll - Subzero runtime source ----------------===;;
+;;
+;;                        The Subzero Code Generator
+;;
+;; This file is distributed under the University of Illinois Open Source
+;; License. See LICENSE.TXT for details.
+;;
+;;===----------------------------------------------------------------------===;;
+;;
+;; This file implements wrappers for particular bitcode instructions that are
+;; too uncommon and complex for a particular target to bother implementing
+;; directly in Subzero target lowering.  This needs to be compiled by some
+;; non-Subzero compiler.
+;;
+;;===----------------------------------------------------------------------===;;
 
 define <4 x float> @Sz_uitofp_v4i32(<4 x i32> %a) {
 entry:

src/IceCfgNode.cpp

@@ -901,8 +901,9 @@ class BundleEmitHelper {
   BundleEmitHelper &operator=(const BundleEmitHelper &) = delete;
 
 public:
-  BundleEmitHelper(Assembler *Asm, const InstList &Insts)
-      : Asm(Asm), End(Insts.end()), BundleLockStart(End),
+  BundleEmitHelper(Assembler *Asm, TargetLowering *Target,
+                   const InstList &Insts)
+      : Asm(Asm), Target(Target), End(Insts.end()), BundleLockStart(End),
         BundleSize(1 << Asm->getBundleAlignLog2Bytes()),
         BundleMaskLo(BundleSize - 1), BundleMaskHi(~BundleMaskLo),
         SizeSnapshotPre(0), SizeSnapshotPost(0) {}
@@ -948,6 +949,7 @@ public:
     BundleLockStart = I;
     SizeSnapshotPre = Asm->getBufferSize();
     Asm->setPreliminary(true);
+    Target->snapshotEmitState();
     assert(isInBundleLockRegion());
   }
   // Update bookkeeping when the bundle_unlock instruction is
@@ -989,10 +991,12 @@ public:
     assert(isInBundleLockRegion());
     Asm->setBufferSize(SizeSnapshotPre);
     Asm->setPreliminary(false);
+    Target->rollbackEmitState();
   }
 
 private:
   Assembler *const Asm;
+  TargetLowering *const Target;
   // End is a sentinel value such that BundleLockStart==End implies
   // that we are not in a bundle_lock region.
   const InstList::const_iterator End;
@@ -1047,7 +1051,7 @@ void CfgNode::emitIAS(Cfg *Func) const {
   // of label bindings, label links, and relocation fixups.  Instead,
   // the first pass just disables all mutation of that state.
 
-  BundleEmitHelper Helper(Asm, Insts);
+  BundleEmitHelper Helper(Asm, Func->getTarget(), Insts);
   InstList::const_iterator End = Insts.end();
   // Retrying indicates that we had to roll back to the bundle_lock
   // instruction to apply padding before the bundle_lock sequence.

src/IceTargetLowering.cpp

@@ -105,7 +105,7 @@ TargetLowering::TargetLowering(Cfg *Func)
     : Func(Func), Ctx(Func->getContext()),
       RandomizeRegisterAllocation(CLRandomizeRegisterAllocation),
       HasComputedFrame(false), CallsReturnsTwice(false), StackAdjustment(0),
-      Context() {}
+      Context(), SnapshotStackAdjustment(0) {}
 
 std::unique_ptr<Assembler> TargetLowering::createAssembler(TargetArch Target,
                                                            Cfg *Func) {

src/IceTargetLowering.h

@@ -192,6 +192,17 @@ public:
       llvm::SmallVectorImpl<int32_t> &Permutation,
       const llvm::SmallBitVector &ExcludeRegisters) const = 0;
 
+  // Save/restore any mutable state for the situation where code
+  // emission needs multiple passes, such as sandboxing or relaxation.
+  // Subclasses may provide their own implementation, but should be
+  // sure to also call the parent class's methods.
+  virtual void snapshotEmitState() {
+    SnapshotStackAdjustment = StackAdjustment;
+  }
+  virtual void rollbackEmitState() {
+    StackAdjustment = SnapshotStackAdjustment;
+  }
+
   virtual void emitVariable(const Variable *Var) const = 0;
 
   // Performs target-specific argument lowering.
@@ -239,6 +250,9 @@ protected:
   // natural location, as arguments are pushed for a function call.
   int32_t StackAdjustment;
   LoweringContext Context;
+
+private:
+  int32_t SnapshotStackAdjustment;
 };
 
 // TargetDataLowering is used for "lowering" data including initializers

src/IceTargetLoweringX8632.cpp

@@ -4118,9 +4118,7 @@ TargetX8632::eliminateNextVectorSextInstruction(Variable *SignExtendedResult) {
   }
 }
 
-void TargetX8632::lowerUnreachable(const InstUnreachable * /*Inst*/) {
-  _ud2();
-}
+void TargetX8632::lowerUnreachable(const InstUnreachable * /*Inst*/) { _ud2(); }
 
 // Turn an i64 Phi instruction into a pair of i32 Phi instructions, to
 // preserve integrity of liveness analysis.  Undef values are also

tests_lit/assembler/x86/sandboxing.ll

@@ -230,3 +230,23 @@ entry:
 ; CHECK: 40: {{.*}} nop
 ; CHECK: 5b: {{.*}} and [[REG]],0xffffffe0
 ; CHECK-NEXT: 5e: {{.*}} call [[REG]]
+
+; Stack adjustment state during an argument push sequence gets
+; properly checkpointed and restored during the two passes, as
+; observed by the stack adjustment for accessing stack-allocated
+; variables.
+define void @checkpoint_restore_stack_adjustment(i32 %arg) {
+entry:
+  call void @call_target()
+  ; bundle boundary
+  call void @checkpoint_restore_stack_adjustment(i32 %arg)
+  ret void
+}
+; CHECK-LABEL: checkpoint_restore_stack_adjustment
+; CHECK: call
+; CHECK: sub esp,0x10
+; The address of %arg should be [esp+0x20], not [esp+0x30].
+; CHECK-NEXT: mov [[REG:.*]],DWORD PTR [esp+0x20]
+; CHECK-NEXT: mov DWORD PTR [esp],[[REG]]
+; CHECK: call
+; CHECK: add esp,0x10