Lower stacksave and restore intrinsics.

tests_lit/llvm2ice_tests/nacl-other-intrinsics.ll

 ; This tests the NaCl intrinsics not related to atomic operations.
 
 ; RUN: %llvm2ice -O2 --verbose none %s | FileCheck %s
 ; RUN: %llvm2ice -Om1 --verbose none %s | FileCheck %s
 
 ; Do another run w/ O2 and a different check-prefix (otherwise O2 and Om1
 ; share the same "CHECK" prefix). This separate run helps check that
 ; some code is optimized out.
 ; RUN: %llvm2ice -O2 --verbose none %s | FileCheck %s --check-prefix=CHECKO2REM
 
@@ skipping 10 matching lines @@
 declare i32 @llvm.nacl.setjmp(i8*)
 declare float @llvm.sqrt.f32(float)
 declare double @llvm.sqrt.f64(double)
 declare void @llvm.trap()
 declare i32 @llvm.ctlz.i32(i32, i1)
 declare i64 @llvm.ctlz.i64(i64, i1)
 declare i32 @llvm.cttz.i32(i32, i1)
 declare i64 @llvm.cttz.i64(i64, i1)
 declare i32 @llvm.ctpop.i32(i32)
 declare i64 @llvm.ctpop.i64(i64)
+declare i8* @llvm.stacksave()
+declare void @llvm.stackrestore(i8*)
 
 define i32 @test_nacl_read_tp() {
 entry:
   %ptr = call i8* @llvm.nacl.read.tp()
   %__1 = ptrtoint i8* %ptr to i32
   ret i32 %__1
 }
 ; CHECK-LABEL: test_nacl_read_tp
 ; CHECK: mov e{{.*}}, dword ptr gs:[0]
 ; CHECKO2REM-LABEL: test_nacl_read_tp
@@ skipping 316 matching lines @@
 entry:
   %r_i64 = call i64 @llvm.ctpop.i64(i64 %x)
   %r = trunc i64 %r_i64 to i32
   ret i32 %r
 }
 ; If there is a trunc, then the mov {{.*}}, 0 is dead and gets optimized out.
 ; CHECKO2REM-LABEL: test_popcount_64_ret_i32
 ; CHECKO2REM: call __popcountdi2
 ; CHECKO2REM-NOT: mov {{.*}}, 0
 
+define void @test_stacksave_noalloca() {
+entry:
+  %sp = call i8* @llvm.stacksave()
+  call void @llvm.stackrestore(i8* %sp)
+  ret void
+}
+; CHECK-LABEL: test_stacksave_noalloca
+; CHECK: mov {{.*}}, esp
+; CHECK: mov esp, {{.*}}
+
+declare i32 @foo(i32 %x)
+
+define void @test_stacksave_multiple(i32 %x) {
+entry:
+  %x_4 = mul i32 %x, 4
+  %sp1 = call i8* @llvm.stacksave()
+  %tmp1 = alloca i8, i32 %x_4, align 4
+
+  %sp2 = call i8* @llvm.stacksave()
+  %tmp2 = alloca i8, i32 %x_4, align 4
+
+  %y = call i32 @foo(i32 %x)
+
+  %sp3 = call i8* @llvm.stacksave()
+  %tmp3 = alloca i8, i32 %x_4, align 4
+
+  %__9 = bitcast i8* %tmp1 to i32*
+  store i32 %y, i32* %__9, align 1
+
+  %__10 = bitcast i8* %tmp2 to i32*
+  store i32 %x, i32* %__10, align 1
+
+  %__11 = bitcast i8* %tmp3 to i32*
+  store i32 %x, i32* %__11, align 1
+
+  call void @llvm.stackrestore(i8* %sp1)
+  ret void
+}
+; CHECK-LABEL: test_stacksave_multiple
+; At least 3 copies of esp, but probably more from having to do the allocas.
+; CHECK: mov {{.*}}, esp
+; CHECK: mov {{.*}}, esp
+; CHECK: mov {{.*}}, esp
+; CHECK: mov esp, {{.*}}
 
 ; ERRORS-NOT: ICE translation error
 ; DUMP-NOT: SZ