llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: None (kimyounhoex1) <details> <summary>Changes</summary> These X86 builtins (`__builtin_ia32_pslldqi128/256_byteshift` and `__builtin_ia32_psrldqi128/256_byteshift`) can now be evaluated at compile time when the shift amount is a constant integer. This improves consistency with other vector shift intrinsics and reduces unnecessary runtime evaluation. Fixes #<!-- -->156494 --- Full diff: https://github.com/llvm/llvm-project/pull/157403.diff 1 Files Affected: - (modified) clang/lib/AST/ExprConstant.cpp (+65) ``````````diff diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp index b4f1e76187e25..2b06705a4870c 100644 --- a/clang/lib/AST/ExprConstant.cpp +++ b/clang/lib/AST/ExprConstant.cpp @@ -12039,6 +12039,71 @@ bool VectorExprEvaluator::VisitCallExpr(const CallExpr *E) { } return Success(APValue(ResultElements.data(), ResultElements.size()), E); } + case X86::BI__builtin_ia32_pslldqi128_byteshift: + case X86::BI__builtin_ia32_psrldqi128_byteshift: { + unsigned BuiltinID = E->getBuiltinCallee(); + + APSInt Amt; + if (!EvaluateInteger(E->getArg(1), Amt, Info)) + break; + unsigned Shift = (unsigned)Amt.getZExtValue(); + + APValue Vec; + if (!Evaluate(Vec, Info, E->getArg(0)) || !Vec.isVector()) + break; + + SmallVector<APValue, 16> ResultElements; + ResultElements.reserve(16); + + bool isLeft = (BuiltinID == X86::BI__builtin_ia32_pslldqi128_byteshift); + + for (unsigned i = 0; i < 16; i++) { + int SrcIdx = -1; + if (isLeft) + SrcIdx = i + Shift; + else if (i >= Shift) + SrcIdx = i - Shift; + + if (SrcIdx >= 0 && (unsigned)SrcIdx < 16) + ResultElements.push_back(Vec.getVectorElt(SrcIdx)); + else + ResultElements.push_back(APValue(0)); + } + return Success(APValue(ResultElements.data(), ResultElements.size()), E); + } + + case X86::BI__builtin_ia32_pslldqi256_byteshift: + case X86::BI__builtin_ia32_psrldqi256_byteshift: { + unsigned BuiltinID = E->getBuiltinCallee(); + + APSInt Amt; + if (!EvaluateInteger(E->getArg(1), Amt, Info)) + break; + unsigned Shift = (unsigned)Amt.getZExtValue(); + + APValue Vec; + if (!Evaluate(Vec, Info, E->getArg(0)) || !Vec.isVector()) + break; + + SmallVector<APValue, 32> ResultElements; + ResultElements.reserve(32); + + bool isLeft = (BuiltinID == X86::BI__builtin_ia32_pslldqi256_byteshift); + + for (unsigned i = 0; i < 32; i++) { + int SrcIdx = -1; + if (isLeft) + SrcIdx = i + Shift; + else if (i >= Shift) + SrcIdx = i - Shift; + + if (SrcIdx >= 0 && (unsigned)SrcIdx < 32) + ResultElements.push_back(Vec.getVectorElt(SrcIdx)); + else + ResultElements.push_back(APValue(0)); + } + return Success(APValue(ResultElements.data(), ResultElements.size()), E); + } } } `````````` </details> https://github.com/llvm/llvm-project/pull/157403 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
