Skip to content

[X86] Fix 32-bit immediate assertion and convert into backend error #123872

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
Open

[X86] Fix 32-bit immediate assertion and convert into backend error #123872

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 4 additions & 5 deletions llvm/lib/Target/X86/X86RegisterInfo.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -965,11 +965,10 @@ X86RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
}

if (MI.getOperand(FIOperandNum+3).isImm()) {
// Offset is a 32-bit integer.
int Imm = (int)(MI.getOperand(FIOperandNum + 3).getImm());
int Offset = FIOffset + Imm;
assert((!Is64Bit || isInt<32>((long long)FIOffset + Imm)) &&
"Requesting 64-bit offset in 32-bit immediate!");
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This assert was checking to see if Offset addition overflowed on x86-64 - haven't we lost that check now?

int64_t Imm = MI.getOperand(FIOperandNum + 3).getImm();
int Offset = FIOffset + (int)Imm;
if (!Is64Bit && !isInt<32>((int64_t)FIOffset + Imm))
MI.emitGenericError("requesting 64-bit offset in 32-bit immediate");
if (Offset != 0 || !tryOptimizeLEAtoMOV(II))
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

If Imm == -FIOffset wouldn't that mean the operand isn't correctly set to zero?

MI.getOperand(FIOperandNum + 3).ChangeToImmediate(Offset);
} else {
Expand Down
17 changes: 17 additions & 0 deletions llvm/test/CodeGen/X86/large-displacements-fastisel.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,17 @@
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
; RUN: llc < %s -mtriple=x86_64 -O=0 | FileCheck %s
@G = global i8 0

; Regression test for #113856 - incorrect FastISel assert

define dso_local i32 @main() #0 {
; CHECK-LABEL: main:
; CHECK: # %bb.0:
; CHECK-NEXT: movl $0, {{[0-9]+}}(%rsp)
; CHECK-NEXT: xorl %eax, %eax
; CHECK-NEXT: retq
%1 = alloca i32, align 4
%G = getelementptr i8, ptr %1, i32 -2147483648
store i32 0, ptr %G, align 4
ret i32 0
}
79 changes: 79 additions & 0 deletions llvm/test/CodeGen/X86/large-displacements.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,79 @@
; RUN: not llc < %s -mtriple=i686 -filetype=null 2>&1 | FileCheck %s -check-prefix=ERR-i686
; RUN: llc < %s -mtriple=x86_64 | FileCheck %s -check-prefix=x86_64

; Regression test for #121932, #113856, #106352, #69365, #25051 which are caused by
; an incorrectly written assertion for 64-bit offsets when compiling for 32-bit X86.

define i32 @main() #0 {
; ERR-i686: error: <unknown>:0:0: requesting 64-bit offset in 32-bit immediate
;
; x86_64-LABEL: main:
; x86_64: # %bb.0: # %entry
; x86_64-NEXT: movl $4294967176, %eax # imm = 0xFFFFFF88
; x86_64-NEXT: subq %rax, %rsp
; x86_64-NEXT: .cfi_def_cfa_offset 4294967184
; x86_64-NEXT: movb $32, -1073741994(%rsp)
; x86_64-NEXT: movb $33, 2147483478(%rsp)
; x86_64-NEXT: movb $34, 1073741654(%rsp)
; x86_64-NEXT: movb $35, -170(%rsp)
; x86_64-NEXT: xorl %eax, %eax
; x86_64-NEXT: movl $4294967176, %ecx # imm = 0xFFFFFF88
; x86_64-NEXT: addq %rcx, %rsp
; x86_64-NEXT: .cfi_def_cfa_offset 8
; x86_64-NEXT: retq
entry:
%a = alloca [1073741824 x i8], align 16
%b = alloca [1073741824 x i8], align 16
%c = alloca [1073741824 x i8], align 16
%d = alloca [1073741824 x i8], align 16

%arrayida = getelementptr inbounds [1073741824 x i8], ptr %a, i64 0, i64 -42
%arrayidb = getelementptr inbounds [1073741824 x i8], ptr %b, i64 0, i64 -42
%arrayidc = getelementptr inbounds [1073741824 x i8], ptr %c, i64 0, i64 -42
%arrayidd = getelementptr inbounds [1073741824 x i8], ptr %d, i64 0, i64 -42

store i8 32, ptr %arrayida, align 2
store i8 33, ptr %arrayidb, align 2
store i8 34, ptr %arrayidc, align 2
store i8 35, ptr %arrayidd, align 2

ret i32 0
}

define i32 @0() #0 {
; ERR-i686: error: <unknown>:0:0: requesting 64-bit offset in 32-bit immediate
;
; x86_64-LABEL: __unnamed_1:
; x86_64: # %bb.0: # %entry
; x86_64-NEXT: movl $4294967176, %eax # imm = 0xFFFFFF88
; x86_64-NEXT: subq %rax, %rsp
; x86_64-NEXT: .cfi_def_cfa_offset 4294967184
; x86_64-NEXT: movb $32, -1073741994(%rsp)
; x86_64-NEXT: movb $33, 2147483478(%rsp)
; x86_64-NEXT: movb $34, 1073741654(%rsp)
; x86_64-NEXT: movb $35, -170(%rsp)
; x86_64-NEXT: xorl %eax, %eax
; x86_64-NEXT: movl $4294967176, %ecx # imm = 0xFFFFFF88
; x86_64-NEXT: addq %rcx, %rsp
; x86_64-NEXT: .cfi_def_cfa_offset 8
; x86_64-NEXT: retq
entry:
%a = alloca [1073741824 x i8], align 16
%b = alloca [1073741824 x i8], align 16
%c = alloca [1073741824 x i8], align 16
%d = alloca [1073741824 x i8], align 16

%arrayida = getelementptr inbounds [1073741824 x i8], ptr %a, i64 0, i64 -42
%arrayidb = getelementptr inbounds [1073741824 x i8], ptr %b, i64 0, i64 -42
%arrayidc = getelementptr inbounds [1073741824 x i8], ptr %c, i64 0, i64 -42
%arrayidd = getelementptr inbounds [1073741824 x i8], ptr %d, i64 0, i64 -42

store i8 32, ptr %arrayida, align 2
store i8 33, ptr %arrayidb, align 2
store i8 34, ptr %arrayidc, align 2
store i8 35, ptr %arrayidd, align 2

ret i32 0
}

attributes #0 = { optnone noinline }