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authorMagnus Lång <[email protected]>2016-05-11 17:25:03 +0200
committerMagnus Lång <[email protected]>2016-05-11 17:35:02 +0200
commitea308bc26d4664705895ff3be31687dc5235cc79 (patch)
tree58f9a87f72d114399ab1f2993bbaa0fd7ea7256d
parent7814ec18b095d40af95f362ff668a68915982e45 (diff)
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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.
-rw-r--r--lib/hipe/main/hipe.erl24
1 files 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'.