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cranelift: Remove brz and brnz (#5630)

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Remove the brz and brnz instructions, as their behavior is now redundant with brif.
This commit is contained in:
Trevor Elliott
2023-01-30 12:34:56 -08:00
committed by GitHub
parent 77cf547f41
commit a5698cedf8
247 changed files with 2947 additions and 3754 deletions
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2
cranelift/codegen/src/isa/x64/inst.isle
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@@ -362,7 +362,7 @@
;; One-way conditional branch: jcond cond target.
;;
;; This instruction is useful when we have conditional jumps depending on
;; more than two conditions, see for instance the lowering of Brz/brnz
;; more than two conditions, see for instance the lowering of Brif
;; with Fcmp inputs.
;;
;; A note of caution: in contexts where the branch target is another

3
cranelift/codegen/src/isa/x64/inst/unwind/systemv.rs
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@@ -184,8 +184,7 @@ mod tests {
let mut pos = FuncCursor::new(&mut func);
pos.insert_block(block0);
pos.ins().brnz(v0, block2, &[]);
pos.ins().jump(block1, &[]);
pos.ins().brif(v0, block2, &[], block1, &[]);
pos.insert_block(block1);
pos.ins().return_(&[]);

35
cranelift/codegen/src/isa/x64/lower.isle
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@@ -2904,41 +2904,6 @@
(jmp_cond (CC.NZ) then else))))
;; Rules for `brz` and `brnz` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 2 (lower_branch (brz (maybe_uextend (icmp cc a b)) _) (two_targets taken not_taken))
(let ((cmp IcmpCondResult (invert_icmp_cond_result (emit_cmp cc a b))))
(emit_side_effect (jmp_cond_icmp cmp taken not_taken))))
(rule 2 (lower_branch (brz (maybe_uextend (fcmp cc a b)) _) (two_targets taken not_taken))
(let ((cmp FcmpCondResult (emit_fcmp (floatcc_inverse cc) a b)))
(emit_side_effect (jmp_cond_fcmp cmp taken not_taken))))
(rule 1 (lower_branch (brz val @ (value_type $I128) _) (two_targets taken not_taken))
(emit_side_effect (jmp_cond_icmp (cmp_zero_i128 (CC.NZ) val) taken not_taken)))
(rule 0 (lower_branch (brz val @ (value_type (ty_int_bool_or_ref)) _) (two_targets taken not_taken))
(emit_side_effect
(with_flags_side_effect (cmp_zero_int_bool_ref val)
(jmp_cond (CC.Z) taken not_taken))))
(rule 2 (lower_branch (brnz (maybe_uextend (icmp cc a b)) _) (two_targets taken not_taken))
(emit_side_effect (jmp_cond_icmp (emit_cmp cc a b) taken not_taken)))
(rule 2 (lower_branch (brnz (maybe_uextend (fcmp cc a b)) _) (two_targets taken not_taken))
(let ((cmp FcmpCondResult (emit_fcmp cc a b)))
(emit_side_effect (jmp_cond_fcmp cmp taken not_taken))))
(rule 1 (lower_branch (brnz val @ (value_type $I128) _) (two_targets taken not_taken))
(emit_side_effect (jmp_cond_icmp (cmp_zero_i128 (CC.Z) val) taken not_taken)))
(rule 0 (lower_branch (brnz val @ (value_type (ty_int_bool_or_ref)) _) (two_targets taken not_taken))
(emit_side_effect
(with_flags_side_effect (cmp_zero_int_bool_ref val)
(jmp_cond (CC.NZ) taken not_taken))))
;; Compare an I128 value to zero, returning a flags result suitable for making a
;; jump decision. The comparison is implemented as `(hi == 0) && (low == 0)`,
;; and the result can be interpreted as follows

9
cranelift/codegen/src/isa/x64/mod.rs
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@@ -261,23 +261,20 @@ mod test {
let v0 = pos.ins().iconst(I32, 0x1234);
pos.set_srcloc(SourceLoc::new(2));
let v1 = pos.ins().iadd(arg0, v0);
pos.ins().brnz(v1, bb1, &[v1]);
pos.ins().jump(bb2, &[]);
pos.ins().brif(v1, bb1, &[v1], bb2, &[]);
pos.insert_block(bb1);
pos.set_srcloc(SourceLoc::new(3));
let v2 = pos.ins().isub(v1, v0);
pos.set_srcloc(SourceLoc::new(4));
let v3 = pos.ins().iadd(v2, bb1_param);
pos.ins().brnz(v1, bb2, &[]);
pos.ins().jump(bb3, &[v3]);
pos.ins().brif(v1, bb2, &[], bb3, &[v3]);
pos.func.layout.set_cold(bb2);
pos.insert_block(bb2);
pos.set_srcloc(SourceLoc::new(5));
let v4 = pos.ins().iadd(v1, v0);
pos.ins().brnz(v4, bb2, &[]);
pos.ins().jump(bb1, &[v4]);
pos.ins().brif(v4, bb2, &[], bb1, &[v4]);
pos.insert_block(bb3);
pos.set_srcloc(SourceLoc::new(6));