Fix the recently added anyregcc convention to handle spilled operands.

Fixes <rdar://15432754> [JS] Assertion: "Folded a def to a non-store!"

The primary purpose of anyregcc is to prevent a patchpoint's call
arguments and return value from being spilled. They must be available
in a register, although the calling convention does not pin the
register. It's up to the front end to avoid using this convention for
calls with more arguments than allocatable registers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194428 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86InstrInfo.cpp

@@ -4207,10 +4207,19 @@ static MachineInstr* foldPatchpoint(MachineFunction &MF,
   MachineInstrBuilder MIB(MF, NewMI);
 
   bool isPatchPoint = MI->getOpcode() == TargetOpcode::PATCHPOINT;
+  // For PatchPoint, the call args are not foldable.
+  unsigned NumCallArgs = MI->getOperand(StartIdx+3).getImm();
   StartIdx = isPatchPoint ?
-             StartIdx + MI->getOperand(StartIdx+3).getImm() + 5 :
+             StartIdx + NumCallArgs + 5 :
              StartIdx + 2;
 
+  // Return false if any operands requested for folding are not foldable (not
+  // part of the stackmap's live values).
+  for (SmallVectorImpl<unsigned>::const_iterator I = Ops.begin(), E = Ops.end();
+       I != E; ++I) {
+    if (*I < StartIdx)
+      return 0;
+  }
   // No need to fold return, the meta data, and function arguments
   for (unsigned i = 0; i < StartIdx; ++i)
     MIB.addOperand(MI->getOperand(i));

test/CodeGen/X86/anyregcc.ll

@@ -8,11 +8,11 @@
 ; Num Constants
 ; CHECK-NEXT:   .long   0
 ; Num Callsites
-; CHECK-NEXT:   .long   6
+; CHECK-NEXT:   .long   7
 
 ; test
 ; CHECK-NEXT:   .long   0
-; CHECK-NEXT:   .long   L{{.*}}-_test
+; CHECK-LABEL:  .long   L{{.*}}-_test
 ; CHECK-NEXT:   .short  0
 ; 3 locations
 ; CHECK-NEXT:   .short  3
@@ -39,7 +39,7 @@ entry:
 
 ; property access 1 - %obj is an anyreg call argument and should therefore be in a register
 ; CHECK-NEXT:   .long   1
-; CHECK-NEXT:   .long   L{{.*}}-_property_access1
+; CHECK-LABEL:  .long   L{{.*}}-_property_access1
 ; CHECK-NEXT:   .short  0
 ; 2 locations
 ; CHECK-NEXT:   .short  2
@@ -62,7 +62,7 @@ entry:
 
 ; property access 2 - %obj is an anyreg call argument and should therefore be in a register
 ; CHECK-NEXT:   .long   2
-; CHECK-NEXT:   .long   L{{.*}}-_property_access2
+; CHECK-LABEL:  .long   L{{.*}}-_property_access2
 ; CHECK-NEXT:   .short  0
 ; 2 locations
 ; CHECK-NEXT:   .short  2
@@ -86,7 +86,7 @@ entry:
 
 ; property access 3 - %obj is a frame index
 ; CHECK-NEXT:   .long   3
-; CHECK-NEXT:   .long   L{{.*}}-_property_access3
+; CHECK-LABEL:  .long   L{{.*}}-_property_access3
 ; CHECK-NEXT:   .short  0
 ; 2 locations
 ; CHECK-NEXT:   .short  2
@@ -110,7 +110,7 @@ entry:
 
 ; anyreg_test1
 ; CHECK-NEXT:   .long   4
-; CHECK-NEXT:   .long   L{{.*}}-_anyreg_test1
+; CHECK-LABEL:  .long   L{{.*}}-_anyreg_test1
 ; CHECK-NEXT:   .short  0
 ; 14 locations
 ; CHECK-NEXT:   .short  14
@@ -193,7 +193,7 @@ entry:
 
 ; anyreg_test2
 ; CHECK-NEXT:   .long   5
-; CHECK-NEXT:   .long   L{{.*}}-_anyreg_test2
+; CHECK-LABEL:  .long   L{{.*}}-_anyreg_test2
 ; CHECK-NEXT:   .short  0
 ; 14 locations
 ; CHECK-NEXT:   .short  14
@@ -274,6 +274,35 @@ entry:
   ret i64 %ret
 }
 
+; Test spilling the return value of an anyregcc call.
+;
+; <rdar://problem/15432754> [JS] Assertion: "Folded a def to a non-store!"
+;
+; CHECK-LABEL: .long 12
+; CHECK-LABEL: .long L{{.*}}-_patchpoint_spilldef
+; CHECK-NEXT: .short 0
+; CHECK-NEXT: .short 3
+; Loc 0: Register (some register that will be spilled to the stack)
+; CHECK-NEXT: .byte  1
+; CHECK-NEXT: .byte  0
+; CHECK-NEXT: .short {{[0-9]+}}
+; CHECK-NEXT: .long  0
+; Loc 1: Register RDI
+; CHECK-NEXT: .byte  1
+; CHECK-NEXT: .byte  0
+; CHECK-NEXT: .short 5
+; CHECK-NEXT: .long  0
+; Loc 1: Register RSI
+; CHECK-NEXT: .byte  1
+; CHECK-NEXT: .byte  0
+; CHECK-NEXT: .short 4
+; CHECK-NEXT: .long  0
+define i64 @patchpoint_spilldef(i64 %p1, i64 %p2, i64 %p3, i64 %p4) {
+entry:
+  %result = tail call anyregcc i64 (i32, i32, i8*, i32, ...)* @llvm.experimental.patchpoint.i64(i32 12, i32 15, i8* inttoptr (i64 0 to i8*), i32 2, i64 %p1, i64 %p2)
+  tail call void asm sideeffect "nop", "~{ax},~{bx},~{cx},~{dx},~{bp},~{si},~{di},~{r8},~{r9},~{r10},~{r11},~{r12},~{r13},~{r14},~{r15}"() nounwind
+  ret i64 %result
+}
+
 declare void @llvm.experimental.patchpoint.void(i32, i32, i8*, i32, ...)
 declare i64 @llvm.experimental.patchpoint.i64(i32, i32, i8*, i32, ...)
-