[llvm] 0ecb12a - [STATEPOINT] Force implicit-def for lr register.

Serguei Katkov via llvm-commits llvm-commits at lists.llvm.org
Mon Nov 15 21:52:21 PST 2021


Author: Serguei Katkov
Date: 2021-11-16T12:52:00+07:00
New Revision: 0ecb12a27ff63eca481cef5ed67ce654a8f111b4

URL: https://github.com/llvm/llvm-project/commit/0ecb12a27ff63eca481cef5ed67ce654a8f111b4
DIFF: https://github.com/llvm/llvm-project/commit/0ecb12a27ff63eca481cef5ed67ce654a8f111b4.diff

LOG: [STATEPOINT] Force implicit-def for lr register.

STATEPOINT instruction behavior is similar to call instruction.
In aarch64 BL instruction implicitly define lr register, so
STATEPOINT instruction should do the same.
However STATEPOINT is a general pseudo instruction and I could not find
a way to override list of implicit defs for specific target.

So this patch post processes inserting STATEPOINT instruction by
adding implisit dead def for lr.

Reviewers: reames, loicottet, ostannard
Reviewed By: reames
Subscribers: danilaml, hiraditya, kristof.beyls, llvm-commits, yrouban
Differential Revision: https://reviews.llvm.org/D111114

Added: 
    

Modified: 
    llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    llvm/test/CodeGen/AArch64/statepoint-call-lowering.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index 4f9ea163fd76..7c7867f508ca 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -2286,9 +2286,15 @@ MachineBasicBlock *AArch64TargetLowering::EmitInstrWithCustomInserter(
   case AArch64::F128CSEL:
     return EmitF128CSEL(MI, BB);
 
+  case TargetOpcode::STATEPOINT:
+    // STATEPOINT is a pseudo instruction which has no implicit defs/uses
+    // while bl call instruction (where statepoint will be lowered at the end)
+    // has implicit def. Add this implicit dead def here as a workaround.
+    MI.addOperand(*MI.getMF(), MachineOperand::CreateReg(AArch64::LR, true,
+                                                         true, false, true));
+    LLVM_FALLTHROUGH;
   case TargetOpcode::STACKMAP:
   case TargetOpcode::PATCHPOINT:
-  case TargetOpcode::STATEPOINT:
     return emitPatchPoint(MI, BB);
 
   case AArch64::CATCHRET:

diff  --git a/llvm/test/CodeGen/AArch64/statepoint-call-lowering.ll b/llvm/test/CodeGen/AArch64/statepoint-call-lowering.ll
index 02d9919b2164..65dc44618d5c 100644
--- a/llvm/test/CodeGen/AArch64/statepoint-call-lowering.ll
+++ b/llvm/test/CodeGen/AArch64/statepoint-call-lowering.ll
@@ -18,9 +18,13 @@ declare void @varargf(i32, ...)
 define i1 @test_i1_return() gc "statepoint-example" {
 ; CHECK-LABEL: test_i1_return:
 ; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    str x30, [sp, #-16]! // 8-byte Folded Spill
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    .cfi_offset w30, -16
 ; CHECK-NEXT:    bl return_i1
-; CHECK-NEXT:  .Ltmp2:
+; CHECK-NEXT:  .Ltmp0:
 ; CHECK-NEXT:    and w0, w0, #0x1
+; CHECK-NEXT:    ldr x30, [sp], #16 // 8-byte Folded Reload
 ; CHECK-NEXT:    ret
 ; This is just checking that a i1 gets lowered normally when there's no extra
 ; state arguments to the statepoint
@@ -33,8 +37,12 @@ entry:
 define i32 @test_i32_return() gc "statepoint-example" {
 ; CHECK-LABEL: test_i32_return:
 ; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    str x30, [sp, #-16]! // 8-byte Folded Spill
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    .cfi_offset w30, -16
 ; CHECK-NEXT:    bl return_i32
-; CHECK-NEXT:  .Ltmp3:
+; CHECK-NEXT:  .Ltmp1:
+; CHECK-NEXT:    ldr x30, [sp], #16 // 8-byte Folded Reload
 ; CHECK-NEXT:    ret
 entry:
   %safepoint_token = tail call token (i64, i32, i32 ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_i32f(i64 0, i32 0, i32 ()* @return_i32, i32 0, i32 0, i32 0, i32 0)
@@ -45,8 +53,12 @@ entry:
 define i32* @test_i32ptr_return() gc "statepoint-example" {
 ; CHECK-LABEL: test_i32ptr_return:
 ; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    str x30, [sp, #-16]! // 8-byte Folded Spill
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    .cfi_offset w30, -16
 ; CHECK-NEXT:    bl return_i32ptr
-; CHECK-NEXT:  .Ltmp4:
+; CHECK-NEXT:  .Ltmp2:
+; CHECK-NEXT:    ldr x30, [sp], #16 // 8-byte Folded Reload
 ; CHECK-NEXT:    ret
 entry:
   %safepoint_token = tail call token (i64, i32, i32* ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_p0i32f(i64 0, i32 0, i32* ()* @return_i32ptr, i32 0, i32 0, i32 0, i32 0)
@@ -57,8 +69,12 @@ entry:
 define float @test_float_return() gc "statepoint-example" {
 ; CHECK-LABEL: test_float_return:
 ; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    str x30, [sp, #-16]! // 8-byte Folded Spill
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    .cfi_offset w30, -16
 ; CHECK-NEXT:    bl return_float
-; CHECK-NEXT:  .Ltmp5:
+; CHECK-NEXT:  .Ltmp3:
+; CHECK-NEXT:    ldr x30, [sp], #16 // 8-byte Folded Reload
 ; CHECK-NEXT:    ret
 entry:
   %safepoint_token = tail call token (i64, i32, float ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_f32f(i64 0, i32 0, float ()* @return_float, i32 0, i32 0, i32 0, i32 0)
@@ -69,8 +85,12 @@ entry:
 define %struct @test_struct_return() gc "statepoint-example" {
 ; CHECK-LABEL: test_struct_return:
 ; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    str x30, [sp, #-16]! // 8-byte Folded Spill
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    .cfi_offset w30, -16
 ; CHECK-NEXT:    bl return_struct
-; CHECK-NEXT:  .Ltmp6:
+; CHECK-NEXT:  .Ltmp4:
+; CHECK-NEXT:    ldr x30, [sp], #16 // 8-byte Folded Reload
 ; CHECK-NEXT:    ret
 entry:
   %safepoint_token = tail call token (i64, i32, %struct ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_structf(i64 0, i32 0, %struct ()* @return_struct, i32 0, i32 0, i32 0, i32 0)
@@ -81,13 +101,13 @@ entry:
 define i1 @test_relocate(i32 addrspace(1)* %a) gc "statepoint-example" {
 ; CHECK-LABEL: test_relocate:
 ; CHECK:       // %bb.0: // %entry
-; CHECK-NEXT:    sub sp, sp, #16
+; CHECK-NEXT:    stp x30, x0, [sp, #-16]! // 8-byte Folded Spill
 ; CHECK-NEXT:    .cfi_def_cfa_offset 16
-; CHECK-NEXT:    str x0, [sp, #8]
+; CHECK-NEXT:    .cfi_offset w30, -16
 ; CHECK-NEXT:    bl return_i1
-; CHECK-NEXT:  .Ltmp7:
+; CHECK-NEXT:  .Ltmp5:
 ; CHECK-NEXT:    and w0, w0, #0x1
-; CHECK-NEXT:    add sp, sp, #16
+; CHECK-NEXT:    ldr x30, [sp], #16 // 8-byte Folded Reload
 ; CHECK-NEXT:    ret
 ; Check that an ununsed relocate has no code-generation impact
 entry:
@@ -100,10 +120,14 @@ entry:
 define void @test_void_vararg() gc "statepoint-example" {
 ; CHECK-LABEL: test_void_vararg:
 ; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    str x30, [sp, #-16]! // 8-byte Folded Spill
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    .cfi_offset w30, -16
 ; CHECK-NEXT:    mov w0, #42
 ; CHECK-NEXT:    mov w1, #43
 ; CHECK-NEXT:    bl varargf
-; CHECK-NEXT:  .Ltmp8:
+; CHECK-NEXT:  .Ltmp6:
+; CHECK-NEXT:    ldr x30, [sp], #16 // 8-byte Folded Reload
 ; CHECK-NEXT:    ret
 ; Check a statepoint wrapping a *void* returning vararg function works
 entry:
@@ -116,9 +140,13 @@ entry:
 define i1 @test_i1_return_patchable() gc "statepoint-example" {
 ; CHECK-LABEL: test_i1_return_patchable:
 ; CHECK:       // %bb.0: // %entry
+; CHECK-NEXT:    str x30, [sp, #-16]! // 8-byte Folded Spill
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    .cfi_offset w30, -16
 ; CHECK-NEXT:    nop
-; CHECK-NEXT:  .Ltmp9:
+; CHECK-NEXT:  .Ltmp7:
 ; CHECK-NEXT:    and w0, w0, #0x1
+; CHECK-NEXT:    ldr x30, [sp], #16 // 8-byte Folded Reload
 ; CHECK-NEXT:    ret
 ; A patchable variant of test_i1_return
 entry:
@@ -141,7 +169,7 @@ define i1 @test_cross_bb(i32 addrspace(1)* %a, i1 %external_cond) gc "statepoint
 ; CHECK-NEXT:    mov w20, w1
 ; CHECK-NEXT:    str x0, [sp, #8]
 ; CHECK-NEXT:    bl return_i1
-; CHECK-NEXT:  .Ltmp10:
+; CHECK-NEXT:  .Ltmp8:
 ; CHECK-NEXT:    tbz w20, #0, .LBB8_2
 ; CHECK-NEXT:  // %bb.1: // %left
 ; CHECK-NEXT:    mov w19, w0
@@ -176,18 +204,21 @@ declare void @consume_attributes(i32, i8* nest, i32, %struct2* byval(%struct2))
 define void @test_attributes(%struct2* byval(%struct2) %s) gc "statepoint-example" {
 ; CHECK-LABEL: test_attributes:
 ; CHECK:       // %bb.0: // %entry
-; CHECK-NEXT:    sub sp, sp, #32
-; CHECK-NEXT:    .cfi_def_cfa_offset 32
+; CHECK-NEXT:    sub sp, sp, #48
+; CHECK-NEXT:    str x30, [sp, #32] // 8-byte Folded Spill
+; CHECK-NEXT:    .cfi_def_cfa_offset 48
+; CHECK-NEXT:    .cfi_offset w30, -16
 ; CHECK-NEXT:    mov x18, xzr
-; CHECK-NEXT:    ldr q0, [sp, #32]
-; CHECK-NEXT:    ldr x8, [sp, #48]
+; CHECK-NEXT:    ldr q0, [sp, #48]
+; CHECK-NEXT:    ldr x8, [sp, #64]
 ; CHECK-NEXT:    mov w0, #42
 ; CHECK-NEXT:    mov w1, #17
 ; CHECK-NEXT:    str q0, [sp]
 ; CHECK-NEXT:    str x8, [sp, #16]
 ; CHECK-NEXT:    bl consume_attributes
-; CHECK-NEXT:  .Ltmp11:
-; CHECK-NEXT:    add sp, sp, #32
+; CHECK-NEXT:  .Ltmp9:
+; CHECK-NEXT:    ldr x30, [sp, #32] // 8-byte Folded Reload
+; CHECK-NEXT:    add sp, sp, #48
 ; CHECK-NEXT:    ret
 entry:
 ; Check that arguments with attributes are lowered correctly.


        


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