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Add uadd_overflow_trap (#5123)

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Add a new instruction uadd_overflow_trap, which is a fused version of iadd_ifcout and trapif. Adding this instruction removes a dependency on the iflags type, and would allow us to move closer to removing it entirely.

The instruction is defined for the i32 and i64 types only, and is currently only used in the legalization of heap_addr.
This commit is contained in:
Trevor Elliott
2022-10-27 09:43:15 -07:00
committed by GitHub
parent 0290a83502
commit 02620441c3
23 changed files with 660 additions and 18 deletions
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20
cranelift/codegen/src/isa/riscv64/inst.isle
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@@ -1847,22 +1847,22 @@
(gen_fabs x ty)
(fpu_rrr (fabs_copy_sign ty) ty x x))
;;; right now only return if overflow.
(decl lower_uadd_overflow (Reg Reg Type) Reg)
;;; Returns the sum in the first register, and the overflow test in the second.
(decl lower_uadd_overflow (Reg Reg Type) ValueRegs)
(rule 1
(lower_uadd_overflow x y $I64)
(let
((tmp Reg (alu_add x y)))
(gen_icmp (IntCC.UnsignedLessThan) tmp x $I64)))
(let ((tmp Reg (alu_add x y))
(test Reg (gen_icmp (IntCC.UnsignedLessThan) tmp x $I64)))
(value_regs tmp test)))
(rule
(lower_uadd_overflow x y (fits_in_32 ty))
(let
((tmp_x Reg (ext_int_if_need $false x ty))
(tmp_y Reg (ext_int_if_need $false y ty))
(sum Reg (alu_add tmp_x tmp_y)))
(alu_srli sum (ty_bits ty))))
(let ((tmp_x Reg (ext_int_if_need $false x ty))
(tmp_y Reg (ext_int_if_need $false y ty))
(sum Reg (alu_add tmp_x tmp_y))
(test Reg (alu_srli sum (ty_bits ty))))
(value_regs sum test)))
(decl inst_output_get (InstOutput u8) ValueRegs)
(extern constructor inst_output_get inst_output_get)