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f329765d23
If we have an add (or an or that is really an add), where one operand is a
FrameIndex and the other operand is a small constant, we can combine the
lowering of the FrameIndex (which is lowered as an add of the FI and a zero
offset) with the constant operand.
Amusingly, this is an old potential improvement entry from
lib/Target/PowerPC/README.txt which had never been resolved. In short, we used
to lower:
%X = alloca { i32, i32 }
%Y = getelementptr {i32,i32}* %X, i32 0, i32 1
ret i32* %Y
as:
addi 3, 1, -8
ori 3, 3, 4
blr
and now we produce:
addi 3, 1, -4
blr
which is much more sensible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224071 91177308-0d34-0410-b5e6-96231b3b80d8
25 lines
536 B
LLVM
25 lines
536 B
LLVM
; RUN: llc -mcpu=ppc64 < %s | FileCheck %s
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target datalayout = "E-m:e-i64:64-n32:64"
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target triple = "powerpc64-unknown-linux-gnu"
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define i32* @test1() {
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%X = alloca { i32, i32 }
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%Y = getelementptr {i32,i32}* %X, i32 0, i32 1
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ret i32* %Y
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; CHECK-LABEL: @test1
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; CHECK: addi 3, 1, -4
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; CHECK: blr
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}
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define i32* @test2() {
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%X = alloca { i32, i32, i32, i32 }
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%Y = getelementptr {i32,i32,i32,i32}* %X, i32 0, i32 3
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ret i32* %Y
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; CHECK-LABEL: @test2
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; CHECK: addi 3, 1, -4
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; CHECK: blr
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}
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