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new 9800032722 checkasm/aarch64: fix operator precedence bug in ARG_STACK
9800032722 is described below
commit 9800032722e6954b982ef1186089e45bddf2a36e
Author: Zhao Zhili <[email protected]>
AuthorDate: Tue Mar 17 16:34:26 2026 +0800
Commit: Zhao Zhili <[email protected]>
CommitDate: Wed Mar 18 13:48:18 2026 +0000
checkasm/aarch64: fix operator precedence bug in ARG_STACK
The expression ((8*(MAX_ARGS - 8) + 15) & ~15 + 16)
evaluates to zero on Apple platforms due to assembler operator
precedence differences. LLVM's integrated assembler uses different
precedence rules depending on the target:
unsigned AsmParser::getBinOpPrecedence(AsmToken::TokenKind K,
MCBinaryExpr::Opcode &Kind) {
bool ShouldUseLogicalShr = MAI.shouldUseLogicalShr();
return IsDarwin ? getDarwinBinOpPrecedence(K, Kind, ShouldUseLogicalShr)
: getGNUBinOpPrecedence(MAI, K, Kind, ShouldUseLogicalShr);
}
In Darwin mode (Apple targets), arithmetic operators (+, -) have
higher precedence than bitwise operators (&, |, ^), similar to C.
In GNU mode (ELF targets), bitwise operators have higher precedence
than arithmetic operators.
---
tests/checkasm/aarch64/checkasm.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tests/checkasm/aarch64/checkasm.S
b/tests/checkasm/aarch64/checkasm.S
index 6d3c738801..4b2db86a9e 100644
--- a/tests/checkasm/aarch64/checkasm.S
+++ b/tests/checkasm/aarch64/checkasm.S
@@ -68,7 +68,7 @@ function checkasm_stack_clobber, export=1
endfunc
// + 16 for stack canary reference
-#define ARG_STACK ((8*(MAX_ARGS - 8) + 15) & ~15 + 16)
+#define ARG_STACK (((8*(MAX_ARGS - 8) + 15) & ~15) + 16)
function checkasm_checked_call, export=1
stp x29, x30, [sp, #-16]!
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