From d4273abb69e487883a612d49025dda2fb40322cd Mon Sep 17 00:00:00 2001 From: Krzysztof Parzyszek Date: Fri, 26 Jan 2018 21:20:04 +0000 Subject: [Hexagon] Make sure that offset on globals matches alignment requirements A correctly aligned address may happen to be separated into a variable part and a constant part, where the constant part does not match the alignment needed in a load/store that uses this address. Such a constant cannot be used as an immediate offset in an indexed instruction. When lowering a global address, make sure that if there is an offset folded into the global, the offset is valid for all uses in load/store instructions. llvm-svn: 323562 --- .../Hexagon/isel-global-offset-alignment.ll | 32 ++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 llvm/test/CodeGen/Hexagon/isel-global-offset-alignment.ll (limited to 'llvm/test/CodeGen/Hexagon/isel-global-offset-alignment.ll') diff --git a/llvm/test/CodeGen/Hexagon/isel-global-offset-alignment.ll b/llvm/test/CodeGen/Hexagon/isel-global-offset-alignment.ll new file mode 100644 index 00000000000..dba7a1ace2b --- /dev/null +++ b/llvm/test/CodeGen/Hexagon/isel-global-offset-alignment.ll @@ -0,0 +1,32 @@ +; RUN: llc -march=hexagon < %s | FileCheck %s + +; This testcase checks that a valid offset is folded into a global address +; when it's used in a load or a store instruction. The store in this code +; is not really properly aligned (bugpoint output from a legal code), but +; what's important is that the offset on the store instructions is a multiple +; of the access size. In this case the actual address is @array+30, but that +; value is not a multiple of 8, so it cannot appear as an immediate in memd. +; Aside from the fact that @array+30 is not a valid address for memd, make +; sure that in a memd instruction the offset field is a multiple of 8. + +; CHECK: r[[BASE:[0-9]+]] = #6 +; CHECK-DAG: memd(r[[BASE]]+##array+24) +; CHECK-DAG: memd(r[[BASE]]+##array+32) + + +target datalayout = "e-m:e-p:32:32:32-a:0-n16:32-i64:64:64-i32:32:32-i16:16:16-i1:8:8-f32:32:32-f64:64:64-v32:32:32-v64:64:64-v512:512:512-v1024:1024:1024-v2048:2048:2048" +target triple = "hexagon" + +@array = external global [1000000 x i16], align 8 + +define void @fred() #0 { +b0: + %v1 = add nsw i32 0, -1 + %v2 = getelementptr inbounds [1000000 x i16], [1000000 x i16]* @array, i32 0, i32 %v1 + %v3 = getelementptr i16, i16* %v2, i32 16 + %v4 = bitcast i16* %v3 to <8 x i16>* + store <8 x i16> zeroinitializer, <8 x i16>* %v4, align 8 + ret void +} + +attributes #0 = { norecurse nounwind } -- cgit v1.2.3