[dev.ssa] cmd/compile: be safer about uintptr/unsafe.Pointer conversions
Make sure that when a pointer value is live across a function
call, we save it as a pointer. (And similarly a uintptr
live across a function call should not be saved as a pointer.)
Add a nasty test case.
This is probably what is preventing the merge from master
to dev.ssa. Signs point to something like this bug happening
in mallocgc.
Change-Id: Ib23fa1251b8d1c50d82c6a448cb4a4fc28219029
Reviewed-on: https://go-review.googlesource.com/16830
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
diff --git a/src/cmd/compile/internal/ssa/rewritegeneric.go b/src/cmd/compile/internal/ssa/rewritegeneric.go
index 174967a..9563e87 100644
--- a/src/cmd/compile/internal/ssa/rewritegeneric.go
+++ b/src/cmd/compile/internal/ssa/rewritegeneric.go
@@ -926,18 +926,22 @@
func rewriteValuegeneric_OpConvert(v *Value, config *Config) bool {
b := v.Block
_ = b
- // match: (Convert (Add64 (Convert ptr) off))
+ // match: (Convert (Add64 (Convert ptr mem) off) mem)
// cond:
// result: (Add64 ptr off)
{
if v.Args[0].Op != OpAdd64 {
- goto end913a7ecf456c00ffbee36c2dbbf0e1af
+ goto endbbc9f1666b4d39a130e1b86f109e7c1b
}
if v.Args[0].Args[0].Op != OpConvert {
- goto end913a7ecf456c00ffbee36c2dbbf0e1af
+ goto endbbc9f1666b4d39a130e1b86f109e7c1b
}
ptr := v.Args[0].Args[0].Args[0]
+ mem := v.Args[0].Args[0].Args[1]
off := v.Args[0].Args[1]
+ if v.Args[1] != mem {
+ goto endbbc9f1666b4d39a130e1b86f109e7c1b
+ }
v.Op = OpAdd64
v.AuxInt = 0
v.Aux = nil
@@ -946,8 +950,31 @@
v.AddArg(off)
return true
}
- goto end913a7ecf456c00ffbee36c2dbbf0e1af
-end913a7ecf456c00ffbee36c2dbbf0e1af:
+ goto endbbc9f1666b4d39a130e1b86f109e7c1b
+endbbc9f1666b4d39a130e1b86f109e7c1b:
+ ;
+ // match: (Convert (Convert ptr mem) mem)
+ // cond:
+ // result: ptr
+ {
+ if v.Args[0].Op != OpConvert {
+ goto end98c5e0ca257eb216989171786f91b42d
+ }
+ ptr := v.Args[0].Args[0]
+ mem := v.Args[0].Args[1]
+ if v.Args[1] != mem {
+ goto end98c5e0ca257eb216989171786f91b42d
+ }
+ v.Op = OpCopy
+ v.AuxInt = 0
+ v.Aux = nil
+ v.resetArgs()
+ v.Type = ptr.Type
+ v.AddArg(ptr)
+ return true
+ }
+ goto end98c5e0ca257eb216989171786f91b42d
+end98c5e0ca257eb216989171786f91b42d:
;
return false
}
