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machinst x64: use xor/xorpss/xorpd to generate zero constants;

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This commit is contained in:
Benjamin Bouvier
2020-07-27 19:26:37 +02:00
committed by Andrew Brown
parent 9a9b5015d0
commit e108f14620
4 changed files with 133 additions and 63 deletions
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20
cranelift/codegen/src/isa/x64/inst/emit.rs
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@@ -2044,8 +2044,7 @@ pub(crate) fn emit(
//
// ;; positive inputs get saturated to INT_MAX; negative ones to INT_MIN, which is
// ;; already in %dst.
// mov 0, %tmp_gpr
// movd/movq %tmp_gpr, %tmp_xmm
// xorpd %tmp_xmm, %tmp_xmm
// cmpss/cmpsd %src, %tmp_xmm
// jnb done
// mov/movaps $INT_MAX, %dst
@@ -2069,8 +2068,7 @@ pub(crate) fn emit(
//
// ;; if positive, it was a real overflow
// check_positive:
// mov 0, %tmp_gpr
// movd/movq %tmp_gpr, %tmp_xmm
// xorpd %tmp_xmm, %tmp_xmm
// cmpss/cmpsd %src, %tmp_xmm
// jnb done
// ud2 trap IntegerOverflow
@@ -2120,11 +2118,10 @@ pub(crate) fn emit(
sink.bind_label(not_nan);
// If the input was positive, saturate to INT_MAX.
// TODO use xorps/xorpd here
let inst = Inst::imm_r(false, 0, *tmp_gpr); // rely on sign-extension to get 0 on 64-bits
inst.emit(sink, flags, state);
// Zero out tmp_xmm.
let inst =
Inst::gpr_to_xmm(cast_op, RegMem::reg(tmp_gpr.to_reg()), *src_size, *tmp_xmm);
Inst::xmm_rm_r(SseOpcode::Xorpd, RegMem::reg(tmp_xmm.to_reg()), *tmp_xmm);
inst.emit(sink, flags, state);
let inst = Inst::xmm_cmp_rm_r(cmp_op, RegMem::reg(src), tmp_xmm.to_reg());
@@ -2194,12 +2191,9 @@ pub(crate) fn emit(
sink.bind_label(check_positive);
// TODO use xorpd
let inst = Inst::imm_r(false, 0, *tmp_gpr);
inst.emit(sink, flags, state);
// Zero out the tmp_xmm register.
let inst =
Inst::gpr_to_xmm(cast_op, RegMem::reg(tmp_gpr.to_reg()), *src_size, *tmp_xmm);
Inst::xmm_rm_r(SseOpcode::Xorpd, RegMem::reg(tmp_xmm.to_reg()), *tmp_xmm);
inst.emit(sink, flags, state);
let inst = Inst::xmm_cmp_rm_r(cmp_op, RegMem::reg(src), tmp_xmm.to_reg());