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x64: Migrate brff and I128 branching instructions to ISLE (#4599)

Browse Source 
https://github.com/bytecodealliance/wasmtime/pull/4599
This commit is contained in:
Trevor Elliott
2022-08-04 08:58:50 -07:00
committed by GitHub
parent 12a9705fbc
commit 1fc11bbe51
12 changed files with 254 additions and 356 deletions
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36
cranelift/codegen/src/isa/x64/lower.isle
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@@ -2872,17 +2872,49 @@
(rule (lower_branch (brif cc (ifcmp a b) _ _) (two_targets taken not_taken))
(side_effect (jmp_cond_icmp (emit_cmp cc a b) taken not_taken)))
;; Rules for `brz` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Rules for `brff` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower_branch (brff cc (ffcmp a b) _ _) (two_targets taken not_taken))
(side_effect (jmp_cond_fcmp (emit_fcmp cc a b) taken not_taken)))
;; Rules for `brz` and `brnz` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower_branch (brz (icmp cc a b) _ _) (two_targets taken not_taken))
(let ((cmp IcmpCondResult (invert_icmp_cond_result (emit_cmp cc a b))))
(side_effect (jmp_cond_icmp cmp taken not_taken))))
;; Rules for `brnz` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower_branch (brz (fcmp cc a b) _ _) (two_targets taken not_taken))
(let ((cmp FcmpCondResult (emit_fcmp (floatcc_inverse cc) a b)))
(side_effect (jmp_cond_fcmp cmp taken not_taken))))
(rule (lower_branch (brz val @ (value_type $I128) _ _) (two_targets taken not_taken))
(side_effect (jmp_cond_icmp (cmp_zero_i128 (CC.NZ) val) taken not_taken)))
(rule (lower_branch (brnz (icmp cc a b) _ _) (two_targets taken not_taken))
(side_effect (jmp_cond_icmp (emit_cmp cc a b) taken not_taken)))
(rule (lower_branch (brnz (fcmp cc a b) _ _) (two_targets taken not_taken))
(let ((cmp FcmpCondResult (emit_fcmp cc a b)))
(side_effect (jmp_cond_fcmp cmp taken not_taken))))
(rule (lower_branch (brnz val @ (value_type $I128) _ _) (two_targets taken not_taken))
(side_effect (jmp_cond_icmp (cmp_zero_i128 (CC.Z) val) 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
;; * CC.Z indicates that the value was non-zero, as one or both of the halves of
;; the value were non-zero
;; * CC.NZ indicates that both halves of the value were 0
(decl cmp_zero_i128 (CC ValueRegs) IcmpCondResult)
(rule (cmp_zero_i128 (cc_nz_or_z cc) val)
(let ((lo Gpr (value_regs_get_gpr val 0))
(hi Gpr (value_regs_get_gpr val 1))
(lo_z Gpr (with_flags_reg (x64_cmp (OperandSize.Size64) (RegMemImm.Imm 0) lo)
(x64_setcc (CC.Z))))
(hi_z Gpr (with_flags_reg (x64_cmp (OperandSize.Size64) (RegMemImm.Imm 0) hi)
(x64_setcc (CC.Z)))))
(icmp_cond_result (x64_test (OperandSize.Size8) lo_z hi_z) cc)))
;; Rules for `bricmp` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;