[llvm] 9255a5c - [TargetLowering] Only inspect attributes in the arguments for ArgListEntry

[Arthur Eubanks via llvm-commits]

Author: Arthur Eubanks
Date: 2021-06-03T15:52:01-07:00
New Revision: 9255a5c1baa6020c009934b4fa342f9f6dbbcc46

URL: https://github.com/llvm/llvm-project/commit/9255a5c1baa6020c009934b4fa342f9f6dbbcc46
DIFF: https://github.com/llvm/llvm-project/commit/9255a5c1baa6020c009934b4fa342f9f6dbbcc46.diff

LOG: [TargetLowering] Only inspect attributes in the arguments for ArgListEntry

Parameter attributes are considered part of the function [1], and like
mismatched calling conventions [2], we can't have the verifier check for
mismatched parameter attributes.

Issues can be diagnosed with D103412.

[1] https://llvm.org/docs/LangRef.html#parameter-attributes
[2] https://llvm.org/docs/FAQ.html#why-does-instcombine-simplifycfg-turn-a-call-to-a-function-with-a-mismatched-calling-convention-into-unreachable-why-not-make-the-verifier-reject-it

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D101806

Added: 
    llvm/test/CodeGen/X86/mismatched-byval.ll

Modified: 
    llvm/docs/ReleaseNotes.rst
    llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index 98117a24fcee9..d96c2080ffa04 100644
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -74,6 +74,13 @@ Changes to building LLVM
 Changes to TableGen
 -------------------
 
+Changes to Backend Code Generation
+----------------------------------
+
+* When lowering calls, only ABI attributes on the call itself are checked, not
+  the caller. Frontends need to make sure to properly set ABI attributes on
+  calls (and always should have).
+
 Changes to the ARM Backend
 --------------------------
 

diff  --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 53b3bcbb42abf..30393298ab728 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -102,29 +102,32 @@ bool TargetLowering::parametersInCSRMatch(const MachineRegisterInfo &MRI,
   return true;
 }
 
-/// Set CallLoweringInfo attribute flags based on a call instruction
-/// and called function attributes.
+/// Set CallLoweringInfo attribute flags based on the call instruction's
+/// argument attributes.
 void TargetLoweringBase::ArgListEntry::setAttributes(const CallBase *Call,
                                                      unsigned ArgIdx) {
-  IsSExt = Call->paramHasAttr(ArgIdx, Attribute::SExt);
-  IsZExt = Call->paramHasAttr(ArgIdx, Attribute::ZExt);
-  IsInReg = Call->paramHasAttr(ArgIdx, Attribute::InReg);
-  IsSRet = Call->paramHasAttr(ArgIdx, Attribute::StructRet);
-  IsNest = Call->paramHasAttr(ArgIdx, Attribute::Nest);
-  IsByVal = Call->paramHasAttr(ArgIdx, Attribute::ByVal);
-  IsPreallocated = Call->paramHasAttr(ArgIdx, Attribute::Preallocated);
-  IsInAlloca = Call->paramHasAttr(ArgIdx, Attribute::InAlloca);
-  IsReturned = Call->paramHasAttr(ArgIdx, Attribute::Returned);
-  IsSwiftSelf = Call->paramHasAttr(ArgIdx, Attribute::SwiftSelf);
-  IsSwiftAsync = Call->paramHasAttr(ArgIdx, Attribute::SwiftAsync);
-  IsSwiftError = Call->paramHasAttr(ArgIdx, Attribute::SwiftError);
-  Alignment = Call->getParamStackAlign(ArgIdx);
+  auto Attrs = Call->getAttributes();
+
+  IsSExt = Attrs.hasParamAttribute(ArgIdx, Attribute::SExt);
+  IsZExt = Attrs.hasParamAttribute(ArgIdx, Attribute::ZExt);
+  IsInReg = Attrs.hasParamAttribute(ArgIdx, Attribute::InReg);
+  IsSRet = Attrs.hasParamAttribute(ArgIdx, Attribute::StructRet);
+  IsNest = Attrs.hasParamAttribute(ArgIdx, Attribute::Nest);
+  IsReturned = Attrs.hasParamAttribute(ArgIdx, Attribute::Returned);
+  IsSwiftSelf = Attrs.hasParamAttribute(ArgIdx, Attribute::SwiftSelf);
+  IsSwiftAsync = Attrs.hasParamAttribute(ArgIdx, Attribute::SwiftAsync);
+  IsSwiftError = Attrs.hasParamAttribute(ArgIdx, Attribute::SwiftError);
+  Alignment = Attrs.getParamStackAlignment(ArgIdx);
+
+  IsByVal = Attrs.hasParamAttribute(ArgIdx, Attribute::ByVal);
   ByValType = nullptr;
   if (IsByVal) {
     ByValType = Call->getParamByValType(ArgIdx);
     if (!Alignment)
       Alignment = Call->getParamAlign(ArgIdx);
   }
+  IsInAlloca = Attrs.hasParamAttribute(ArgIdx, Attribute::InAlloca);
+  IsPreallocated = Attrs.hasParamAttribute(ArgIdx, Attribute::Preallocated);
   PreallocatedType = nullptr;
   if (IsPreallocated)
     PreallocatedType = Call->getParamPreallocatedType(ArgIdx);

diff  --git a/llvm/test/CodeGen/X86/mismatched-byval.ll b/llvm/test/CodeGen/X86/mismatched-byval.ll
new file mode 100644
index 0000000000000..f03e347848c6d
--- /dev/null
+++ b/llvm/test/CodeGen/X86/mismatched-byval.ll
@@ -0,0 +1,45 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=x86_64-unknown | FileCheck %s
+
+; This tests that we only look at the call site for ABI attributes, so f and f2 should codegen 
diff erently
+
+define void @b(i8* byval(i8) %p) {
+; CHECK-LABEL: b:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    retq
+    ret void
+}
+
+define void @f(i8 %p) {
+; CHECK-LABEL: f:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    subq $24, %rsp
+; CHECK-NEXT:    .cfi_def_cfa_offset 32
+; CHECK-NEXT:    movb {{[0-9]+}}(%rsp), %al
+; CHECK-NEXT:    movb %al, (%rsp)
+; CHECK-NEXT:    callq b at PLT
+; CHECK-NEXT:    addq $24, %rsp
+; CHECK-NEXT:    .cfi_def_cfa_offset 8
+; CHECK-NEXT:    retq
+    %a = alloca i8
+    ;store i8 %p, i8* %a
+    call void @b(i8* byval(i8) %a)
+    ret void
+}
+
+define void @f2(i8 %p) {
+; CHECK-LABEL: f2:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    .cfi_def_cfa_offset 16
+; CHECK-NEXT:    leaq {{[0-9]+}}(%rsp), %rdi
+; CHECK-NEXT:    callq b at PLT
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:    .cfi_def_cfa_offset 8
+; CHECK-NEXT:    retq
+    %a = alloca i8
+    ;store i8 %p, i8* %a
+    call void @b(i8* %a)
+    ret void
+}
+