From: Lynn Boger Date: Tue, 11 Aug 2020 16:04:25 +0000 (-0400) Subject: [release-branch.go1.14] cmd/internal/obj/ppc64: don't remove NOP in assembler X-Git-Tag: go1.14.9~3 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=32dc9f7a0a8002bf844f4bc1104402c93334ed8f;p=gostls13.git [release-branch.go1.14] cmd/internal/obj/ppc64: don't remove NOP in assembler Previously, the assembler removed NOPs from the Prog list in obj9.go. NOPs shouldn't be removed if they were added as an inline mark, as described in the issue below. Fixes #40766 Once the NOPs were left in the Prog list, some instructions were flagged as invalid because they had an operand which was not represented in optab. In order to preserve the previous assembler behavior, entries were added to optab for those operand cases. They were not flagged as errors before because the NOP instructions were removed before the code to check the valid opcode/operand combinations. Change-Id: Iae5145f94459027cf458e914d7c5d6089807ccf8 Reviewed-on: https://go-review.googlesource.com/c/go/+/247842 Run-TryBot: Lynn Boger TryBot-Result: Gobot Gobot Reviewed-by: Paul Murphy Reviewed-by: Michael Munday Reviewed-by: Keith Randall (cherry picked from commit 7d7bd5abc7f7ac901830b79496f63ce86895e262) Reviewed-on: https://go-review.googlesource.com/c/go/+/248382 Run-TryBot: Dmitri Shuralyov --- diff --git a/src/cmd/internal/obj/ppc64/asm9.go b/src/cmd/internal/obj/ppc64/asm9.go index 149604574b..0472375e48 100644 --- a/src/cmd/internal/obj/ppc64/asm9.go +++ b/src/cmd/internal/obj/ppc64/asm9.go @@ -607,6 +607,9 @@ var optab = []Optab{ {obj.APCDATA, C_LCON, C_NONE, C_NONE, C_LCON, 0, 0, 0}, {obj.AFUNCDATA, C_SCON, C_NONE, C_NONE, C_ADDR, 0, 0, 0}, {obj.ANOP, C_NONE, C_NONE, C_NONE, C_NONE, 0, 0, 0}, + {obj.ANOP, C_LCON, C_NONE, C_NONE, C_NONE, 0, 0, 0}, // NOP operand variations added for #40689 + {obj.ANOP, C_REG, C_NONE, C_NONE, C_NONE, 0, 0, 0}, // to preserve previous behavior + {obj.ANOP, C_FREG, C_NONE, C_NONE, C_NONE, 0, 0, 0}, {obj.ADUFFZERO, C_NONE, C_NONE, C_NONE, C_LBRA, 11, 4, 0}, // same as ABR/ABL {obj.ADUFFCOPY, C_NONE, C_NONE, C_NONE, C_LBRA, 11, 4, 0}, // same as ABR/ABL {obj.APCALIGN, C_LCON, C_NONE, C_NONE, C_NONE, 0, 0, 0}, // align code diff --git a/src/cmd/internal/obj/ppc64/obj9.go b/src/cmd/internal/obj/ppc64/obj9.go index 7135488f9d..a2f16f2e2a 100644 --- a/src/cmd/internal/obj/ppc64/obj9.go +++ b/src/cmd/internal/obj/ppc64/obj9.go @@ -427,7 +427,6 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) { /* * find leaf subroutines - * strip NOPs * expand RET * expand BECOME pseudo */ @@ -557,10 +556,7 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) { q = p q1 = p.Pcond if q1 != nil { - for q1.As == obj.ANOP { - q1 = q1.Link - p.Pcond = q1 - } + // NOPs are not removed due to #40689. if q1.Mark&LEAF == 0 { q1.Mark |= LABEL @@ -587,9 +583,8 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) { continue case obj.ANOP: - q1 = p.Link - q.Link = q1 /* q is non-nop */ - q1.Mark |= p.Mark + // NOPs are not removed due to + // #40689 continue default: