administrator/blaise
1
0
Fork 0
Code Issues Pull requests Actions Packages Projects Releases Wiki Activity

refactor(codegen-native): extract EmitSretBufferSlideDown

Browse source 
Phase 1 item 7 of the de-duplication plan.  The post-call sret return-buffer
slide-down (`if HTotal > 0 then` reclaim the arg-hoist region and re-push the
fat pointer at (%rsp)) was byte-identical at the tail of all three
interface-sret return paths: EmitIntfSretCall, EmitIntfSretMethodCall, and
EmitClassIntfSretMethodCall.  Collapse into EmitSretBufferSlideDown(AHoistTotal).

Proven byte-identical: native .s for an interface-returning program (direct and
chained `MakeGreeter('Hi ').Greet('there')`, exercising the sret-return-with-
hoisted-arg slide) is identical to pre-refactor HEAD.  All four self-host
fixpoints pass; full suite OK (3853 tests) on both QBE-built and native-built
test runners.
This commit is contained in:
Graeme Geldenhuys 2026-06-27 09:13:57 +01:00
parent fdcce09254
commit 8e52f7769f
1 changed files with 21 additions and 24 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

45
compiler/src/main/pascal/blaise.codegen.native.x86_64.pas
View file

@ -393,6 +393,12 @@ type
offset: subtract the (non-zero) low bound, then multiply by the element
size. The read-path subscript sites all spell this the same way. }
procedure EmitStaticElemScale(ASAT: TStaticArrayTypeDesc);
{ After an sret interface call whose argument hoist left AHoistTotal bytes
of hoist region BELOW the 16-byte return buffer at (%rsp): reclaim the
hoist region and leave the fat pointer (obj, itab) re-pushed at (%rsp) so
the caller's `fat pointer at (%rsp)` contract holds. No-op when
AHoistTotal is 0 (nothing was hoisted, buffer already at the top). }
procedure EmitSretBufferSlideDown(AHoistTotal: Integer);
{ Lower a Write/WriteLn call (ANewline = WriteLn). }
procedure EmitWrite(ACall: TProcCall; ANewline: Boolean);
{ Lower a for loop. }
@ -10796,6 +10802,18 @@ begin
Self.Emit(Format(#9'imulq $%d, %%rax', [ASAT.ElementType.RawSize()]));
end;
procedure TX86_64Backend.EmitSretBufferSlideDown(AHoistTotal: Integer);
begin
if AHoistTotal > 0 then
begin
Self.Emit(#9'movq (%rsp), %rax');
Self.Emit(#9'movq 8(%rsp), %rcx');
Self.Emit(Format(#9'addq $%d, %%rsp', [16 + AHoistTotal]));
Self.Emit(#9'pushq %rcx');
Self.Emit(#9'pushq %rax');
end;
end;
procedure TX86_64Backend.EmitStmt(AStmt: TASTStmt);
var
PC: TProcCall;
@ -15780,14 +15798,7 @@ begin
and the region), then slide the buffer down over the region so the
caller's contract holds. }
Self.EmitHoistEpilogue(ACall.Args, HD, HK, HTotal, 16, False);
if HTotal > 0 then
begin
Self.Emit(#9'movq (%rsp), %rax');
Self.Emit(#9'movq 8(%rsp), %rcx');
Self.Emit(Format(#9'addq $%d, %%rsp', [16 + HTotal]));
Self.Emit(#9'pushq %rcx');
Self.Emit(#9'pushq %rax');
end;
Self.EmitSretBufferSlideDown(HTotal);
HD.Free();
HK.Free();
end;
@ -15962,14 +15973,7 @@ begin
{ Post-call: release hoisted values, then slide the buffer down over the
hoist region so the caller's `fat pointer at (%rsp)` contract holds. }
Self.EmitHoistEpilogue(ACall.Args, HD, HK, HTotal, 16, False);
if HTotal > 0 then
begin
Self.Emit(#9'movq (%rsp), %rax');
Self.Emit(#9'movq 8(%rsp), %rcx');
Self.Emit(Format(#9'addq $%d, %%rsp', [16 + HTotal]));
Self.Emit(#9'pushq %rcx');
Self.Emit(#9'pushq %rax');
end;
Self.EmitSretBufferSlideDown(HTotal);
HD.Free();
HK.Free();
end;
@ -16071,14 +16075,7 @@ begin
{ Post-call: release hoisted values, then slide the buffer down over the
hoist region so the caller's `fat pointer at (%rsp)` contract holds. }
Self.EmitHoistEpilogue(ACall.Args, HD, HK, HTotal, 16, False);
if HTotal > 0 then
begin
Self.Emit(#9'movq (%rsp), %rax');
Self.Emit(#9'movq 8(%rsp), %rcx');
Self.Emit(Format(#9'addq $%d, %%rsp', [16 + HTotal]));
Self.Emit(#9'pushq %rcx');
Self.Emit(#9'pushq %rax');
end;
Self.EmitSretBufferSlideDown(HTotal);
HD.Free();
HK.Free();
end;