Test signed right shift on pre-Constantinople EVMs via IR codegen#16755
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msooseth wants to merge 1 commit into
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Test signed right shift on pre-Constantinople EVMs via IR codegen#16755msooseth wants to merge 1 commit into
msooseth wants to merge 1 commit into
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YulUtilFunctions::shiftRightSignedFunctionDynamic emits either sar(bits, value) on Constantinople+ or a manual xor/div/xor fallback on earlier EVMs. The fallback path was not directly exercised by any existing semantic test under via-IR: shift_right_garbled_signed_v1.sol is explicitly compileViaYul: false, and bitwise_shifting_constantinople*.sol are >=constantinople. Add a test that pins down signed right shift semantics on <constantinople with compileViaYul: also, covering int8 and int256 boundaries (sign bit set/unset, INT*_MIN, INT*_MAX, shift amounts 0, 1, type bits-1, type bits, and >= 256). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Summary
YulUtilFunctions::shiftRightSignedFunctionDynamichas two arms:sar(bits, value)on Constantinople+, and a manualxor(div(xor(value, mask), divisor), mask)fallback on earlier EVMs.operators/shifts/shift_right_garbled_signed_v1.solis explicitlycompileViaYul: false.operators/shifts/bitwise_shifting_constantinople*.solare>=constantinople.operators/shifts/shift_right_signed_pre_constantinople.solwithEVMVersion: <constantinopleandcompileViaYul: also, covering int8 and int256 boundaries (sign bit set/unset, INT*_MIN, INT*_MAX, shift amounts 0, 1, type-bits-1, type-bits, and ≥ 256).shift_right_garbled_signed_v2.sol) so Solidity's cleanup-on-read does the sign extension — avoiding the ABI v2 decoder rejecting non-sign-extended int8 calldata.No production code changes; this is pure coverage.
Test plan
isoltest --evm-version byzantium -t "semanticTests/operators/shifts/shift_right_signed_pre_constantinople"→ OK (both legacy and via-IR pipelines).