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[MC] Fix emission in asm of alignment 2^32. #98688

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Merged
merged 2 commits into from
Jul 17, 2024
Merged

[MC] Fix emission in asm of alignment 2^32. #98688

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0ce5e3f
[AsmPrinter] Fix emission in asm of alignment 2^32.
efriedma-quic Jul 12, 2024
e252523
fixup! address review comments.
efriedma-quic Jul 16, 2024
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12 changes: 6 additions & 6 deletions llvm/lib/MC/MCAsmStreamer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -254,7 +254,7 @@ class MCAsmStreamer final : public MCStreamer {
void emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr,
SMLoc Loc = SMLoc()) override;

void emitAlignmentDirective(unsigned ByteAlignment,
void emitAlignmentDirective(uint64_t ByteAlignment,
std::optional<int64_t> Value, unsigned ValueSize,
unsigned MaxBytesToEmit);

Expand Down Expand Up @@ -1478,23 +1478,23 @@ void MCAsmStreamer::emitFill(const MCExpr &NumValues, int64_t Size,
EmitEOL();
}

void MCAsmStreamer::emitAlignmentDirective(unsigned ByteAlignment,
void MCAsmStreamer::emitAlignmentDirective(uint64_t ByteAlignment,
std::optional<int64_t> Value,
unsigned ValueSize,
unsigned MaxBytesToEmit) {
if (MAI->useDotAlignForAlignment()) {
if (!isPowerOf2_32(ByteAlignment))
if (!isPowerOf2_64(ByteAlignment))
report_fatal_error("Only power-of-two alignments are supported "
"with .align.");
OS << "\t.align\t";
OS << Log2_32(ByteAlignment);
OS << Log2_64(ByteAlignment);
EmitEOL();
return;
}

// Some assemblers don't support non-power of two alignments, so we always
// emit alignments as a power of two if possible.
if (isPowerOf2_32(ByteAlignment)) {
if (isPowerOf2_64(ByteAlignment)) {
switch (ValueSize) {
default:
llvm_unreachable("Invalid size for machine code value!");
Expand All @@ -1511,7 +1511,7 @@ void MCAsmStreamer::emitAlignmentDirective(unsigned ByteAlignment,
llvm_unreachable("Unsupported alignment size!");
}

OS << Log2_32(ByteAlignment);
OS << Log2_64(ByteAlignment);

if (Value.has_value() || MaxBytesToEmit) {
if (Value.has_value()) {
Expand Down
14 changes: 14 additions & 0 deletions llvm/test/CodeGen/X86/global-with-max-align.ll
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@@ -0,0 +1,14 @@
; RUN: llc -mtriple=x86_64 < %s | FileCheck %s
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Consider adding a file-level comment what the test is about.


; Make sure alignment of 2^32 isn't truncated to zero.

; CHECK: .globl g1
; CHECK-NEXT: .p2align 32, 0x0
; CHECK: .globl g2
; CHECK-NEXT: .p2align 32, 0x0
; CHECK: .globl g3
; CHECK-NEXT: .p2align 32, 0x0

@g1 = global i32 0, align 4294967296
@g2 = global i32 33, align 4294967296
@g3 = constant i32 44, align 4294967296
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