diff --git a/lib/Target/X86/X86TargetTransformInfo.cpp b/lib/Target/X86/X86TargetTransformInfo.cpp index 437f63d3280..c04964d60bf 100644 --- a/lib/Target/X86/X86TargetTransformInfo.cpp +++ b/lib/Target/X86/X86TargetTransformInfo.cpp @@ -915,6 +915,9 @@ unsigned X86TTI::getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm, switch (Opcode) { default: return TCC_Free; case Instruction::GetElementPtr: + // Always hoist the base address of a GetElementPtr. This prevents the + // creation of new constants for every base constant that gets constant + // folded with the offset. if (Idx == 0) return 2 * TCC_Basic; return TCC_Free; diff --git a/test/Transforms/ConstantHoisting/X86/const-base-addr.ll b/test/Transforms/ConstantHoisting/X86/const-base-addr.ll new file mode 100644 index 00000000000..ffd51b5c068 --- /dev/null +++ b/test/Transforms/ConstantHoisting/X86/const-base-addr.ll @@ -0,0 +1,24 @@ +; RUN: opt -S -consthoist < %s | FileCheck %s + +target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-apple-macosx10.9.0" + +%T = type { i32, i32, i32, i32 } + +; Test if even cheap base addreses are hoisted. +define i32 @test1() nounwind { +; CHECK-LABEL: @test1 +; CHECK: %const = bitcast i32 12345678 to i32 +; CHECK: %1 = inttoptr i32 %const to %T* +; CHECK: %addr1 = getelementptr %T* %1, i32 0, i32 1 + %addr1 = getelementptr %T* inttoptr (i32 12345678 to %T*), i32 0, i32 1 + %tmp1 = load i32* %addr1 + %addr2 = getelementptr %T* inttoptr (i32 12345678 to %T*), i32 0, i32 2 + %tmp2 = load i32* %addr2 + %addr3 = getelementptr %T* inttoptr (i32 12345678 to %T*), i32 0, i32 3 + %tmp3 = load i32* %addr3 + %tmp4 = add i32 %tmp1, %tmp2 + %tmp5 = add i32 %tmp3, %tmp4 + ret i32 %tmp5 +} +