From ea308bc26d4664705895ff3be31687dc5235cc79 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Magnus=20L=C3=A5ng?= Date: Wed, 11 May 2016 17:25:03 +0200 Subject: hipe_llvm: Disable floats for x86 A bug in LLVM miscompiles x86 functions that have floats are spilled to stack. We work around it by disabling (inlined) floats when using llvm on x86. Once a LLVM version in which the bug is fixed is released, we can make the workaround conditional depending on the version. --- lib/hipe/main/hipe.erl | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/lib/hipe/main/hipe.erl b/lib/hipe/main/hipe.erl index 01b7f34b3c..77cf39460a 100644 --- a/lib/hipe/main/hipe.erl +++ b/lib/hipe/main/hipe.erl @@ -1480,18 +1480,25 @@ opt_expansions(TargetArch) -> [{o1, o1_opts(TargetArch)}, {o2, o2_opts(TargetArch)}, {o3, o3_opts(TargetArch)}, - {to_llvm, llvm_opts(o3)}, - {{to_llvm, o0}, llvm_opts(o0)}, - {{to_llvm, o1}, llvm_opts(o1)}, - {{to_llvm, o2}, llvm_opts(o2)}, - {{to_llvm, o3}, llvm_opts(o3)}, + {to_llvm, llvm_opts(o3, TargetArch)}, + {{to_llvm, o0}, llvm_opts(o0, TargetArch)}, + {{to_llvm, o1}, llvm_opts(o1, TargetArch)}, + {{to_llvm, o2}, llvm_opts(o2, TargetArch)}, + {{to_llvm, o3}, llvm_opts(o3, TargetArch)}, {x87, [x87, inline_fp]}, {inline_fp, case TargetArch of %% XXX: Temporary until x86 has sse2 x86 -> [x87, inline_fp]; _ -> [inline_fp] end}]. -llvm_opts(O) -> - [to_llvm, {llvm_opt, O}, {llvm_llc, O}]. +llvm_opts(O, TargetArch) -> + Base = [to_llvm, {llvm_opt, O}, {llvm_llc, O}], + case TargetArch of + %% A llvm bug present in 3.4 through (at least) 3.8 miscompiles x86 + %% functions that have floats are spilled to stack by clobbering the process + %% pointer (ebp) trying to realign the stack pointer. + x86 -> [no_inline_fp | Base]; + _ -> Base + end. %% This expands "basic" options, which may be tested early and cannot be %% in conflict with options found in the source code. @@ -1521,7 +1528,8 @@ expand_options(Opts, TargetArch) -> proplists:normalize(Opts, [{negations, opt_negations()}, {aliases, opt_aliases()}, {expand, opt_basic_expansions()}, - {expand, opt_expansions(TargetArch)}]). + {expand, opt_expansions(TargetArch)}, + {negations, opt_negations()}]). -spec check_options(comp_options()) -> 'ok'. -- cgit v1.2.3