[SystemZ] Add the CoveredBySubRegs bit to GPR64, GPR128 and FPR128 registers.

This bit is needed in order for the CalleeSavedRegs list to automatically
include the super registers if all of their subregs are present.

Thanks to Wei Mi for initially indicating this deficiency in the SystemZ
backend.

Review: Ulrich Weigand.
https://bugs.llvm.org/show_bug.cgi?id=34550

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313023 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/SystemZ/SystemZRegisterInfo.td b/lib/Target/SystemZ/SystemZRegisterInfo.td
index 52ba1a584017a4f67dc21c4596430f7a364d44e9..a1cfaf699401962d2ac8ef496cb881455bf9f2e5 100644 (file)
--- a/lib/Target/SystemZ/SystemZRegisterInfo.td
+++ b/lib/Target/SystemZ/SystemZRegisterInfo.td
@@ -65,6 +65,7 @@ class GPR64<bits<16> num, string n, GPR32 low, GPR32 high>
  : SystemZRegWithSubregs<n, [low, high]> {
   let HWEncoding = num;
   let SubRegIndices = [subreg_l32, subreg_h32];
+  let CoveredBySubRegs = 1;
 }
 
 // 8 even-odd pairs of GPR64s.
@@ -72,6 +73,7 @@ class GPR128<bits<16> num, string n, GPR64 low, GPR64 high>
  : SystemZRegWithSubregs<n, [low, high]> {
   let HWEncoding = num;
   let SubRegIndices = [subreg_l64, subreg_h64];
+  let CoveredBySubRegs = 1;
 }
 
 // General-purpose registers
@@ -194,6 +196,7 @@ class FPR128<bits<16> num, string n, FPR64 low, FPR64 high>
  : SystemZRegWithSubregs<n, [low, high]> {
   let HWEncoding = num;
   let SubRegIndices = [subreg_l64, subreg_h64];
+  let CoveredBySubRegs = 1;
 }
 
 // Floating-point registers.  Registers 16-31 require the vector facility.

diff --git a/test/CodeGen/SystemZ/loop-03.ll b/test/CodeGen/SystemZ/loop-03.ll
new file mode 100644 (file)
index 0000000..b95e1ae
--- /dev/null
+++ b/test/CodeGen/SystemZ/loop-03.ll
@@ -0,0 +1,126 @@
+; Test that loops with sufficient registers do not reload or spill on
+; stack. These cases include calls and it is necessary to have the GR128 /
+; FP128 registers part of the callee saved registers list in order to avoid
+; spilling / reloading.
+;
+; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z13 | FileCheck %s
+
+%0 = type { %0*, %0*, %0*, i32, %1*, i64, i64, i64, i64, i64, i64, %2, %5, %7 }
+%1 = type { i32, i32, i32 (%1*, i64, i32)*, i32 (%1*, i64, i64, i32, i8**)*, i32 (%1*, i64, i64, i64, i32)*, i32 (%1*)*, void (i8*)*, i8*, i8* }
+%2 = type { i64, i64, %3** }
+%3 = type { %4*, i64 }
+%4 = type { i64, i8* }
+%5 = type { i64, i64, %6** }
+%6 = type { i64, %4*, i32, i64, i8* }
+%7 = type { i64, i64, %8** }
+%8 = type { i64, i64*, i64*, %4*, i64, i32*, %5, i32, i64, i64 }
+
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i32, i1)
+
+define void @fun0(%0*) {
+; CHECK-LABEL: .LBB0_4
+; CHECK: =>  This Inner Loop Header: Depth=2
+; CHECK-NOT: 16-byte Folded Spill
+; CHECK-NOT: 16-byte Folded Reload
+
+  %2 = load i64, i64* undef, align 8
+  %3 = udiv i64 128, %2
+  %4 = mul i64 %3, %2
+  %5 = load i64, i64* undef, align 8
+  switch i32 undef, label %36 [
+    i32 1, label %6
+    i32 2, label %7
+    i32 3, label %8
+    i32 4, label %9
+    i32 5, label %10
+    i32 6, label %11
+  ]
+
+; <label>:6:                                      ; preds = %1
+  br label %12
+
+; <label>:7:                                      ; preds = %1
+  br label %12
+
+; <label>:8:                                      ; preds = %1
+  unreachable
+
+; <label>:9:                                      ; preds = %1
+  unreachable
+
+; <label>:10:                                     ; preds = %1
+  unreachable
+
+; <label>:11:                                     ; preds = %1
+  unreachable
+
+; <label>:12:                                     ; preds = %7, %6
+  %13 = getelementptr inbounds %0, %0* %0, i64 0, i32 5
+  br label %14
+
+; <label>:14:                                     ; preds = %31, %12
+  %15 = phi i64 [ undef, %31 ], [ %5, %12 ]
+  %16 = phi i64 [ %35, %31 ], [ undef, %12 ]
+  %17 = load i64, i64* %13, align 8
+  %18 = icmp ult i64 %15, %17
+  %19 = select i1 %18, i64 %15, i64 %17
+  %20 = udiv i64 %19, %4
+  %21 = icmp ugt i64 %20, 1
+  %22 = select i1 %21, i64 %20, i64 1
+  %23 = sub i64 %22, 0
+  br label %24
+
+; <label>:24:                                     ; preds = %24, %14
+  %25 = phi i64 [ %23, %14 ], [ %27, %24 ]
+  call void @llvm.memcpy.p0i8.p0i8.i64(i8* undef, i8* nonnull undef, i64 %4, i32 1, i1 false)
+  %26 = getelementptr inbounds i8, i8* null, i64 %4
+  store i8* %26, i8** undef, align 8
+  %27 = add i64 %25, -4
+  %28 = icmp eq i64 %27, 0
+  br i1 %28, label %31, label %24
+
+; <label>:29:                                     ; preds = %24
+  br i1 undef, label %31, label %30
+
+; <label>:30:                                     ; preds = %29
+  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %26, i8* nonnull undef, i64 %4, i32 1, i1 false)
+  br label %31
+
+; <label>:31:                                     ; preds = %30, %29
+  %32 = call signext i32 undef(%1* undef, i64 %16, i32 signext 8)
+  %33 = icmp eq i64 undef, 0
+  %34 = select i1 %33, i64 0, i64 %19
+  %35 = add i64 %34, %16
+  br i1 %33, label %36, label %14
+
+; <label>:36:                                     ; preds = %31, %1
+  ret void
+}
+
+declare fp128 @llvm.pow.f128(fp128, fp128)
+
+define void @fun1(fp128*) {
+; CHECK-LABEL: .LBB1_2
+; CHECK: =>This Inner Loop Header: Depth=1
+; CHECK-NOT: 16-byte Folded Spill
+; CHECK-NOT: 16-byte Folded Reload
+; CHECK-LABEL: .LBB1_3
+
+  br i1 undef, label %7, label %2
+
+; <label>:2:                                      ; preds = %2, %1
+  %3 = phi fp128 [ %5, %2 ], [ 0xL00000000000000000000000000000000, %1 ]
+  %4 = tail call fp128 @llvm.pow.f128(fp128 0xL00000000000000000000000000000000, fp128 0xL00000000000000000000000000000000) #2
+  %5 = fadd fp128 %3, %4
+  %6 = icmp eq i64 undef, 0
+  br i1 %6, label %7, label %2
+
+; <label>:7:                                      ; preds = %2, %1
+  %8 = phi fp128 [ 0xL00000000000000000000000000000000, %1 ], [ %5, %2 ]
+  %9 = fadd fp128 0xL00000000000000000000000000000000, %8
+  %10 = fadd fp128 0xL00000000000000000000000000000000, %9
+  %11 = fadd fp128 0xL00000000000000000000000000000000, %10
+  %12 = tail call fp128 @llvm.pow.f128(fp128 %11, fp128 0xL00000000000000000000000000000000) #2
+  store fp128 %12, fp128* %0, align 8
+  ret void
+}