From 7bba7d0efc69ff3da5a064a5d77513dd5aca0f15 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Thu, 13 Sep 2012 18:31:27 +0000 Subject: Fix the TCRETURNmi64 bug differently. Add a PatFrag to match X86tcret using 6 fixed registers or less. This avoids folding loads into TCRETURNmi64 using 7 or more volatile registers. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163819 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/CodeGen/X86/tailcall-64.ll | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'test/CodeGen/X86/tailcall-64.ll') diff --git a/test/CodeGen/X86/tailcall-64.ll b/test/CodeGen/X86/tailcall-64.ll index 7030753415..df7af69a99 100644 --- a/test/CodeGen/X86/tailcall-64.ll +++ b/test/CodeGen/X86/tailcall-64.ll @@ -93,4 +93,43 @@ define { i64, i64 } @crash(i8* %this) { ret { i64, i64 } %mrv7 } +; Check that we can fold an indexed load into a tail call instruction. +; CHECK: fold_indexed_load +; CHECK: leaq (%rsi,%rsi,4), %[[RAX:r..]] +; CHECK: movq _func_table@GOTPCREL(%rip), %[[RCX:r..]] +; CHECK: jmpq *16(%[[RCX]],%[[RAX]],8) # TAILCALL +%struct.funcs = type { i32 (i8*, i32*, i32)*, i32 (i8*)*, i32 (i8*)*, i32 (i8*, i32)*, i32 } +@func_table = external global [0 x %struct.funcs] +define void @fold_indexed_load(i8* %mbstr, i64 %idxprom) nounwind uwtable ssp { +entry: + %dsplen = getelementptr inbounds [0 x %struct.funcs]* @func_table, i64 0, i64 %idxprom, i32 2 + %x1 = load i32 (i8*)** %dsplen, align 8 + %call = tail call i32 %x1(i8* %mbstr) nounwind + ret void +} +; Fold an indexed load into the tail call instruction. +; Calling a varargs function with 6 arguments requires 7 registers (%al is the +; vector count for varargs functions). This leaves %r11 as the only available +; scratch register. +; +; It is not possible to fold an indexed load into TCRETURNmi64 in that case. +; +; typedef int (*funcptr)(void*, ...); +; extern const funcptr funcs[]; +; int f(int n) { +; return funcs[n](0, 0, 0, 0, 0, 0); +; } +; +; CHECK: rdar12282281 +; CHECK: jmpq *%r11 # TAILCALL +@funcs = external constant [0 x i32 (i8*, ...)*] + +define i32 @rdar12282281(i32 %n) nounwind uwtable ssp { +entry: + %idxprom = sext i32 %n to i64 + %arrayidx = getelementptr inbounds [0 x i32 (i8*, ...)*]* @funcs, i64 0, i64 %idxprom + %0 = load i32 (i8*, ...)** %arrayidx, align 8 + %call = tail call i32 (i8*, ...)* %0(i8* null, i32 0, i32 0, i32 0, i32 0, i32 0) nounwind + ret i32 %call +} -- cgit v1.2.3