Author: Martin Storsjö Date: 2022-04-11T16:44:22-07:00 New Revision: c62053979489ccb002efe411c3af059addcb5d7d
URL: https://github.com/llvm/llvm-project/commit/c62053979489ccb002efe411c3af059addcb5d7d DIFF: https://github.com/llvm/llvm-project/commit/c62053979489ccb002efe411c3af059addcb5d7d.diff LOG: [AArch64] Fix the upper limit for folded address offsets for COFF In COFF, the immediates in IMAGE_REL_ARM64_PAGEBASE_REL21 relocations are limited to 21 bit signed, i.e. the offset has to be less than (1 << 20). The previous limit did intend to cover for this case, but had missed that the 21 bit field was signed. This fixes issue https://github.com/llvm/llvm-project/issues/54753. Differential Revision: https://reviews.llvm.org/D123160 (cherry picked from commit 8d7a17b7c8b7151b8453903db96fc7f45d9b1bae) Added: Modified: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp llvm/lib/Target/AArch64/GISel/AArch64PreLegalizerCombiner.cpp llvm/test/CodeGen/AArch64/fold-global-offsets.ll Removed: ################################################################################ diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp index 3008466159bb2..77260c89df115 100644 --- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp +++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp @@ -17115,13 +17115,14 @@ static SDValue performGlobalAddressCombine(SDNode *N, SelectionDAG &DAG, // Check whether folding this offset is legal. It must not go out of bounds of // the referenced object to avoid violating the code model, and must be - // smaller than 2^21 because this is the largest offset expressible in all - // object formats. + // smaller than 2^20 because this is the largest offset expressible in all + // object formats. (The IMAGE_REL_ARM64_PAGEBASE_REL21 relocation in COFF + // stores an immediate signed 21 bit offset.) // // This check also prevents us from folding negative offsets, which will end // up being treated in the same way as large positive ones. They could also // cause code model violations, and aren't really common enough to matter. - if (Offset >= (1 << 21)) + if (Offset >= (1 << 20)) return SDValue(); const GlobalValue *GV = GN->getGlobal(); diff --git a/llvm/lib/Target/AArch64/GISel/AArch64PreLegalizerCombiner.cpp b/llvm/lib/Target/AArch64/GISel/AArch64PreLegalizerCombiner.cpp index d3f4130d2ba14..3730030aa140e 100644 --- a/llvm/lib/Target/AArch64/GISel/AArch64PreLegalizerCombiner.cpp +++ b/llvm/lib/Target/AArch64/GISel/AArch64PreLegalizerCombiner.cpp @@ -162,13 +162,14 @@ static bool matchFoldGlobalOffset(MachineInstr &MI, MachineRegisterInfo &MRI, // Check whether folding this offset is legal. It must not go out of bounds of // the referenced object to avoid violating the code model, and must be - // smaller than 2^21 because this is the largest offset expressible in all - // object formats. + // smaller than 2^20 because this is the largest offset expressible in all + // object formats. (The IMAGE_REL_ARM64_PAGEBASE_REL21 relocation in COFF + // stores an immediate signed 21 bit offset.) // // This check also prevents us from folding negative offsets, which will end // up being treated in the same way as large positive ones. They could also // cause code model violations, and aren't really common enough to matter. - if (NewOffset >= (1 << 21)) + if (NewOffset >= (1 << 20)) return false; Type *T = GV->getValueType(); diff --git a/llvm/test/CodeGen/AArch64/fold-global-offsets.ll b/llvm/test/CodeGen/AArch64/fold-global-offsets.ll index c57de0d796bda..aa5435c4fd6b3 100644 --- a/llvm/test/CodeGen/AArch64/fold-global-offsets.ll +++ b/llvm/test/CodeGen/AArch64/fold-global-offsets.ll @@ -84,23 +84,23 @@ define [2 x i64] @f4() { define i64 @f5() { ; CHECK-LABEL: f5: ; CHECK: // %bb.0: -; CHECK-NEXT: adrp x8, x2+2097144 -; CHECK-NEXT: ldr x0, [x8, :lo12:x2+2097144] +; CHECK-NEXT: adrp x8, x2+1048568 +; CHECK-NEXT: ldr x0, [x8, :lo12:x2+1048568] ; CHECK-NEXT: ret ; ; GISEL-LABEL: f5: ; GISEL: // %bb.0: -; GISEL-NEXT: adrp x8, x2+2097144 -; GISEL-NEXT: ldr x0, [x8, :lo12:x2+2097144] +; GISEL-NEXT: adrp x8, x2+1048568 +; GISEL-NEXT: ldr x0, [x8, :lo12:x2+1048568] ; GISEL-NEXT: ret - %l = load i64, i64* getelementptr ([16777216 x i64], [16777216 x i64]* @x2, i64 0, i64 262143) + %l = load i64, i64* getelementptr ([16777216 x i64], [16777216 x i64]* @x2, i64 0, i64 131071) ret i64 %l } define i64 @f6() { ; CHECK-LABEL: f6: ; CHECK: // %bb.0: -; CHECK-NEXT: mov w8, #2097152 +; CHECK-NEXT: mov w8, #1048576 ; CHECK-NEXT: adrp x9, x2 ; CHECK-NEXT: add x9, x9, :lo12:x2 ; CHECK-NEXT: ldr x0, [x9, x8] @@ -108,12 +108,12 @@ define i64 @f6() { ; ; GISEL-LABEL: f6: ; GISEL: // %bb.0: -; GISEL-NEXT: mov w8, #2097152 +; GISEL-NEXT: mov w8, #1048576 ; GISEL-NEXT: adrp x9, x2 ; GISEL-NEXT: add x9, x9, :lo12:x2 ; GISEL-NEXT: ldr x0, [x9, x8] ; GISEL-NEXT: ret - %l = load i64, i64* getelementptr ([16777216 x i64], [16777216 x i64]* @x2, i64 0, i64 262144) + %l = load i64, i64* getelementptr ([16777216 x i64], [16777216 x i64]* @x2, i64 0, i64 131072) ret i64 %l } _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
