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[Hexagon] Guard the generation of lookup table 

The llvm flag "-hexagon-emit-lookup-tables" guards the generation
of lookup table generated from a switch statement.
Differential Revision: https://reviews.llvm.org/D34819

llvm-svn: 306877
This commit is contained in:
Sumanth Gundapaneni 2017-06-30 20:54:24 +00:00
parent 03ab2e2b1c
commit d2dd79bf84
4 changed files with 78 additions and 0 deletions
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8
llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.cpp
View File

@ -21,6 +21,10 @@ using namespace llvm;
#define DEBUG_TYPE "hexagontti"
static cl::opt<bool> EmitLookupTables("hexagon-emit-lookup-tables",
cl::init(true), cl::Hidden,
cl::desc("Control lookup table emission on Hexagon target"));
TargetTransformInfo::PopcntSupportKind
HexagonTTIImpl::getPopcntSupport(unsigned IntTyWidthInBit) const {
// Return Fast Hardware support as every input < 64 bits will be promoted
@ -70,3 +74,7 @@ int HexagonTTIImpl::getUserCost(const User *U,
return TargetTransformInfo::TCC_Free;
return BaseT::getUserCost(U, Operands);
}
bool HexagonTTIImpl::shouldBuildLookupTables() const {
return EmitLookupTables;
}

3
llvm/lib/Target/Hexagon/HexagonTargetTransformInfo.h
View File

@ -63,6 +63,9 @@ public:
/// @}
int getUserCost(const User *U, ArrayRef<const Value *> Operands);
// Hexagon specific decision to generate a lookup table.
bool shouldBuildLookupTables() const;
};
} // end namespace llvm

5
llvm/test/Transforms/SimplifyCFG/Hexagon/lit.local.cfg Normal file
View File

@ -0,0 +1,5 @@
config.suffixes = ['.ll']
targets = set(config.root.targets_to_build.split())
if not 'Hexagon' in targets:
config.unsupported = True

62
llvm/test/Transforms/SimplifyCFG/Hexagon/switch-to-lookup-table.ll Normal file
View File

@ -0,0 +1,62 @@
; RUN: opt -S -O2 < %s | FileCheck %s -check-prefix=ENABLE
; RUN: opt -S -hexagon-emit-lookup-tables=true -O2 < %s | FileCheck %s -check-prefix=ENABLE
; RUN: opt -S -hexagon-emit-lookup-tables=false -O2 < %s | FileCheck %s -check-prefix=DISABLE
; ENABLE: @{{.*}} = private unnamed_addr constant [6 x i32] [i32 9, i32 20, i32 14, i32 22, i32 12, i32 5]
; DISABLE-NOT: @{{.*}} = private unnamed_addr constant [6 x i32] [i32 9, i32 20, i32 14, i32 22, i32 12, i32 5]
; DISABLE : = phi i32 [ 19, %{{.*}} ], [ 5, %{{.*}} ], [ 12, %{{.*}} ], [ 22, %{{.*}} ], [ 14, %{{.*}} ], [ 20, %{{.*}} ], [ 9, %{{.*}} ]
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-unknown--elf"
; Function Attrs: noinline nounwind
define i32 @foo(i32 %x) #0 section ".tcm_text" {
entry:
%retval = alloca i32, align 4
%x.addr = alloca i32, align 4
store i32 %x, i32* %x.addr, align 4
%0 = load i32, i32* %x.addr, align 4
switch i32 %0, label %sw.default [
i32 0, label %sw.bb
i32 1, label %sw.bb1
i32 2, label %sw.bb2
i32 3, label %sw.bb3
i32 4, label %sw.bb4
i32 5, label %sw.bb5
]
sw.bb: ; preds = %entry
store i32 9, i32* %retval, align 4
br label %return
sw.bb1: ; preds = %entry
store i32 20, i32* %retval, align 4
br label %return
sw.bb2: ; preds = %entry
store i32 14, i32* %retval, align 4
br label %return
sw.bb3: ; preds = %entry
store i32 22, i32* %retval, align 4
br label %return
sw.bb4: ; preds = %entry
store i32 12, i32* %retval, align 4
br label %return
sw.bb5: ; preds = %entry
store i32 5, i32* %retval, align 4
br label %return
sw.default: ; preds = %entry
store i32 19, i32* %retval, align 4
br label %return
return: ; preds = %sw.default, %sw.bb5, %sw.bb4, %sw.bb3, %sw.bb2, %sw.bb1, %sw.bb
%1 = load i32, i32* %retval, align 4
ret i32 %1
}
attributes #0 = { noinline nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="hexagonv60" "target-features"="-hvx-double,-long-calls" "unsafe-fp-math"="false" "use-soft-float"="false" }