From: Josh Bleecher Snyder Date: Fri, 17 Jun 2016 19:30:27 +0000 (-0700) Subject: cmd/internal/obj: reduce per-architecture opcode space X-Git-Tag: go1.8beta1~1831 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=9b88fac00cdbb4025a24fd20e87be121785da579;p=gostls13.git cmd/internal/obj: reduce per-architecture opcode space s390x took up the last available chunk of int16 opcodes. There are RISC-V and sparc64 ports in progress out of tree, and there will likely be other architectures. Reduce the opcode space to allow more architectures to fit without increasing to int32. This is the smallest power of two that accomodates all existing architectures. All else being equal, smaller is better--smaller numbers are easier to generate immediates for and easier on the eyes when debugging. Change-Id: I4d0824b28913892fbd0579d3f90bea34e44c8946 Reviewed-on: https://go-review.googlesource.com/24223 Run-TryBot: Josh Bleecher Snyder TryBot-Result: Gobot Gobot Reviewed-by: Minux Ma --- diff --git a/src/cmd/internal/obj/link.go b/src/cmd/internal/obj/link.go index edd45d411d..e5ed859eb1 100644 --- a/src/cmd/internal/obj/link.go +++ b/src/cmd/internal/obj/link.go @@ -300,7 +300,7 @@ const ( // Subspaces are aligned to a power of two so opcodes can be masked // with AMask and used as compact array indices. const ( - ABase386 = (1 + iota) << 12 + ABase386 = (1 + iota) << 10 ABaseARM ABaseAMD64 ABasePPC64 @@ -308,7 +308,7 @@ const ( ABaseMIPS64 ABaseS390X - AllowedOpCodes = 1 << 12 // The number of opcodes available for any given architecture. + AllowedOpCodes = 1 << 10 // The number of opcodes available for any given architecture. AMask = AllowedOpCodes - 1 // AND with this to use the opcode as an array index. )