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IRGen: Large types reg2mem - Fix visitUncheckedTrivialBitCastInst #73626

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Merged
merged 3 commits into from
May 16, 2024
Merged

IRGen: Large types reg2mem - Fix visitUncheckedTrivialBitCastInst #73626

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1258563
IRGen: Large types reg2mem - Fix visitUncheckedTrivialBitCastInst
aschwaighofer May 14, 2024
f32c534
Fix-up the new test expectation
aschwaighofer May 14, 2024
cb68a9b
Try to fix the windows test failure
aschwaighofer May 15, 2024
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12 changes: 9 additions & 3 deletions lib/IRGen/LoadableByAddress.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3799,17 +3799,23 @@ class AssignAddressToDef : SILInstructionVisitor<AssignAddressToDef> {

void visitUncheckedTrivialBitCastInst(UncheckedTrivialBitCastInst *bc) {
auto builder = assignment.getBuilder(bc->getIterator());

if (assignment.isLargeLoadableType(bc->getType()) &&
!assignment.isLargeLoadableType(bc->getOperand()->getType())) {
// Curious case of an imported C union.
// The union is imported as a struct that has no fields.
// When we access union members we instead bitcast to the union member
// type.
auto addr = assignment.createAllocStack(bc->getType());
auto opdAddr = builder.createUncheckedAddrCast(
bc->getLoc(), addr, bc->getOperand()->getType().getAddressType());

// We expect the "in" type to be larger or equal in size to the "out"
// type. See IRGenSILFunction::visitUncheckedTrivialBitCastInst.
// We therefore must use the bigger type, i.e the operand type, to create
// a stack allocation.
auto opdAddr = assignment.createAllocStack(bc->getOperand()->getType());
builder.createStore(bc->getLoc(), bc->getOperand(), opdAddr,
StoreOwnershipQualifier::Unqualified);
auto addr = builder.createUncheckedAddrCast(
bc->getLoc(), opdAddr, bc->getType().getAddressType());
assignment.mapValueToAddress(origValue, addr);
assignment.markForDeletion(bc);
return;
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37 changes: 37 additions & 0 deletions test/IRGen/Inputs/large_c.h
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Expand Up @@ -40,3 +40,40 @@ typedef struct _ContainerType {
char x1;
ContainedType l[10];
} __attribute__((packed)) ContainerType;

typedef unsigned char arr_t[32];

typedef enum : unsigned int {
entry_0 = 0,
entry_1 = 1,
entry_2 = 2,
entry_3 = 3,
entry_4 = 4,
entry_5 = 5,
entry_6 = 6,
entry_7 = 7,
entry_8 = 8,
entry_9 = 9,
entry_10 = 10,
entry_11 = 11,
entry_12 = 12,
entry_13 = 13,
entry_14 = 14,
entry_15 = 15,
entry_16 = 16,
entry_17 = 17,
entry_18 = 18,
entry_invalid = 255,
} enum_t;

typedef union {
struct {
enum_t slot;
arr_t buf;
} in;
struct {
int result;
arr_t buff;
unsigned char cnt;
} out;
} union_t;
4 changes: 2 additions & 2 deletions test/IRGen/large_union.swift
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Expand Up @@ -7,13 +7,13 @@ public func test1(_ s: some_struct) -> some_struct {
}
// CHECK: sil @$s1t5test1ySo11some_structaADF : $@convention(thin) (@in_guaranteed some_struct) -> @out some_struct {
// CHECK-NOT: unchecked_trivial_bitcast
// CHECK: unchecked_addr_cast {{.*}} : $*some_struct.__Unnamed_struct_out to $*some_struct
// CHECK: unchecked_addr_cast {{.*}} : $*some_struct to $*some_struct.__Unnamed_struct_out
// CHECK-NOT: unchecked_trivial_bitcast
// CHECK: } // end sil function '$s1t5test1ySo11some_structaADF'

// CHECK: sil @$s1t5test2yySo11some_structazF : $@convention(thin) (@inout some_struct) -> () {
// CHECK-NOT: unchecked_trivial_bitcast
// CHECK: unchecked_addr_cast {{.*}} : $*some_struct.__Unnamed_struct_out to $*some_struct
// CHECK: unchecked_addr_cast {{.*}} : $*some_struct to $*some_struct.__Unnamed_struct_out
// CHECK-NOT: unchecked_trivial_bitcast
// CHECK: } // end sil function '$s1t5test2yySo11some_structazF'

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27 changes: 27 additions & 0 deletions test/IRGen/loadable_by_address_reg2mem.sil
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Expand Up @@ -269,3 +269,30 @@ bb0(%0 : $*C1, %1 : $*Small):
%t = tuple ()
return %t : $()
}

sil @use : $@convention(thin) (UInt32) -> ()

// We need to make sure we use the bigger alloc_stack for the address of
// unchecked_trivial_bit_cast. A bitcast can go from bigger to smaller type.

// CHECK: sil @test11 : $@convention(thin) (@in union_t) -> () {
// CHECK-NOT: unchecked_addr_cast %1 : $*union_t.__Unnamed_struct_in to $*union_t
// CHECK: unchecked_addr_cast {{.*}} : $*union_t to $*union_t.__Unnamed_struct_in
// CHECK: } // end sil function 'test11'

sil @test11 : $@convention(thin) (@in union_t) -> () {
bb0(%0 : $*union_t):
%1 = alloc_stack $union_t
%2 = alloc_stack $union_t
copy_addr [take] %0 to [init] %2 : $*union_t
%4 = load %2 : $*union_t
%7 = unchecked_trivial_bit_cast %4 : $union_t to $union_t.__Unnamed_struct_in
%8 = struct_extract %7 : $union_t.__Unnamed_struct_in, #union_t.__Unnamed_struct_in.slot
%10 = struct_extract %8 : $enum_t, #enum_t.rawValue
%11 = function_ref @use : $@convention(thin) (UInt32) -> ()
%12 = apply %11(%10) : $@convention(thin) (UInt32) -> ()
%13 = tuple ()
dealloc_stack %2 : $*union_t
dealloc_stack %1 : $*union_t
return %13 : $()
}