maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[RISCV] Add zext.h/zext.w to RISCVTTIImpl::getIntImmCostInst. 

If we have these instructions, we don't need to hoist the immediate
for an AND that would match them.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D107783
This commit is contained in:
Craig Topper 2021-08-18 09:32:10 -07:00
parent 7557d6c896
commit f70238914a
2 changed files with 44 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
View File

@ -52,8 +52,15 @@ InstructionCost RISCVTTIImpl::getIntImmCostInst(unsigned Opcode, unsigned Idx,
// split up large offsets in GEP into better parts than ConstantHoisting
// can.
return TTI::TCC_Free;
case Instruction::Add:
case Instruction::And:
// zext.h
if (Imm == UINT64_C(0xffff) && ST->hasStdExtZbb())
return TTI::TCC_Free;
// zext.w
if (Imm == UINT64_C(0xffffffff) && ST->hasStdExtZbb())
return TTI::TCC_Free;
LLVM_FALLTHROUGH;
case Instruction::Add:
case Instruction::Or:
case Instruction::Xor:
case Instruction::Mul:

36
llvm/test/Transforms/ConstantHoisting/RISCV/immediates.ll
View File

@ -36,3 +36,39 @@ define i128 @test4(i128 %a) nounwind {
%2 = add i128 %1, 12297829382473034410122878
ret i128 %2
}
; Check that we hoist zext.h without Zbb.
define i32 @test5(i32 %a) nounwind {
; CHECK-LABEL: test5
; CHECK: %const = bitcast i32 65535 to i32
%1 = and i32 %a, 65535
%2 = and i32 %1, 65535
ret i32 %2
}
; Check that we don't hoist zext.h with 65535 with Zbb.
define i32 @test6(i32 %a) nounwind "target-features"="+experimental-zbb" {
; CHECK-LABEL: test6
; CHECK: and i32 %a, 65535
%1 = and i32 %a, 65535
%2 = and i32 %1, 65535
ret i32 %2
}
; Check that we hoist zext.w without Zba.
define i64 @test7(i64 %a) nounwind {
; CHECK-LABEL: test7
; CHECK: %const = bitcast i64 4294967295 to i64
%1 = and i64 %a, 4294967295
%2 = and i64 %1, 4294967295
ret i64 %2
}
; Check that we don't hoist zext.w with Zba.
define i64 @test8(i64 %a) nounwind "target-features"="+experimental-zbb" {
; CHECK-LABEL: test8
; CHECK: and i64 %a, 4294967295
%1 = and i64 %a, 4294967295
%2 = and i64 %1, 4294967295
ret i64 %2
}