From: Julian Seward <jseward@acm.org>
Date: Mon, 10 Jan 2005 16:51:14 +0000 (+0000)
Subject: Run x86 host with FPU in 53-bit precision mode (non default).
X-Git-Tag: svn/VALGRIND_3_0_0~1100
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=41029893963032d2f03a67230ca60a1cf0e33ef8;p=thirdparty%2Fvalgrind.git

Run x86 host with FPU in 53-bit precision mode (non default).


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@3218
---

diff --git a/coregrind/core_asm.h b/coregrind/core_asm.h
index 4b49b50fd5..6b78520f07 100644
--- a/coregrind/core_asm.h
+++ b/coregrind/core_asm.h
@@ -52,6 +52,7 @@
 #define VG_TRC_INNER_FASTMISS     37 /* TRC only; means fast-cache miss. */
 #define VG_TRC_INNER_COUNTERZERO  41 /* TRC only; means bb ctr == 0 */
 #define VG_TRC_UNRESUMABLE_SIGNAL 43 /* TRC only; got sigsegv/sigbus */
+#define VG_TRC_INVARIANT_FAILED   47 /* TRC only; invariant violation */
 
 
 /* Constants for the fast translation lookup cache. */
diff --git a/coregrind/vg_scheduler.c b/coregrind/vg_scheduler.c
index 6ba20c08c5..9ec067fba8 100644
--- a/coregrind/vg_scheduler.c
+++ b/coregrind/vg_scheduler.c
@@ -287,6 +287,7 @@ UInt run_thread_for_a_while ( ThreadId tid )
    volatile UInt sz_vex   = (UInt) sizeof VG_(threads)[tid].arch.vex;
    volatile UInt sz_vexsh = (UInt) sizeof VG_(threads)[tid].arch.vex_shadow;
    volatile UInt sz_spill = (UInt) sizeof VG_(threads)[tid].arch.vex_spill;
+   /* volatile UInt zz = VG_(threads)[tid].arch.vex.guest_EIP; */
 
    /* Paranoia */
    vg_assert(VG_(is_valid_tid)(tid));
@@ -340,6 +341,14 @@ UInt run_thread_for_a_while ( ThreadId tid )
 
    vg_assert(!scheduler_jmpbuf_valid);
 
+   if (trc == VG_TRC_INVARIANT_FAILED) {
+      /* To see the bb causing this to fail, set VG_SCHEDULING_QUANTUM to 1, 
+         and make zz be the program counter at entry to this fn. */
+      /* VG_(translate)(tid,zz,True); */
+      VG_(core_panic)
+         ("host invariant state failure in VEX-generated code");
+   }
+
    done_this_time = (Int)dispatch_ctr_SAVED - (Int)VG_(dispatch_ctr) - 0;
 
    vg_assert(done_this_time >= 0);
diff --git a/coregrind/x86/dispatch.S b/coregrind/x86/dispatch.S
index 7505f8c459..5040534498 100644
--- a/coregrind/x86/dispatch.S
+++ b/coregrind/x86/dispatch.S
@@ -68,9 +68,10 @@ VG_(run_innerloop):
 	movl	(%ebp, %esi, 1), %eax
 
 	/* set host FPU control word to the default mode expected 
-	   by VEX-generated code. */
+           by VEX-generated code.  See comments in libvex.h for
+           more info. */
 	finit
-	pushl	$0x037F
+	pushl	$0x027F
 	fldcw	(%esp)
 	addl	$4, %esp
 	
@@ -123,19 +124,33 @@ dispatch_boring:
 	jmp	dispatch_exceptional
 
 	
-fast_lookup_failed:
-	/* %EIP is up to date here since dispatch_boring dominates */
-	addl	$1, VG_(dispatch_ctr)
-	movl	$VG_TRC_INNER_FASTMISS, %eax
-	jmp	run_innerloop_exit
 
-counter_is_zero:
-	/* %EIP is up to date here since dispatch_boring dominates */
-	addl	$1, VG_(dispatch_ctr)
-	movl	$VG_TRC_INNER_COUNTERZERO, %eax
-	jmp	run_innerloop_exit
-	
-run_innerloop_exit:
+/* All exits from the dispatcher go through here.  %eax holds
+   the return value. 
+*/
+run_innerloop_exit: 
+	/* We're leaving.  Check that nobody messed with
+           %mxcsr or %fpucw.  We can't mess with %eax here as it
+	   holds the tentative return value, but any other is OK. */
+	pushl	$0
+	fstcw	(%esp)
+	cmpl	$0x027F, (%esp)
+	popl	%esi /* get rid of the word without trashing %eflags */
+	jnz	invariant_violation
+	pushl	$0
+	stmxcsr	(%esp)
+	andl	$0xFFFFFFC0, (%esp)  /* mask out status flags */
+	cmpl	$0x1F80, (%esp)
+	popl	%esi
+	jnz	invariant_violation
+	/* otherwise we're OK */
+	jmp	run_innerloop_exit_REALLY
+
+invariant_violation:
+	movl	$VG_TRC_INVARIANT_FAILED, %eax
+	jmp	run_innerloop_exit_REALLY
+
+run_innerloop_exit_REALLY:
 	popl	%ebp
 	popl	%edi
 	popl	%esi
@@ -161,6 +176,18 @@ dispatch_exceptional:
 	movl	%ebp, %eax
 	jmp	run_innerloop_exit
 
+fast_lookup_failed:
+	/* %EIP is up to date here since dispatch_boring dominates */
+	addl	$1, VG_(dispatch_ctr)
+	movl	$VG_TRC_INNER_FASTMISS, %eax
+	jmp	run_innerloop_exit
+
+counter_is_zero:
+	/* %EIP is up to date here since dispatch_boring dominates */
+	addl	$1, VG_(dispatch_ctr)
+	movl	$VG_TRC_INNER_COUNTERZERO, %eax
+	jmp	run_innerloop_exit
+
 	
 /* Let the linker know we don't need an executable stack */
 .section .note.GNU-stack,"",@progbits