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[SystemZ] Fix register ordering for BinaryRRF instructions

Authored by zhanjunl on May 16 2016, 3:21 PM.



The ordering of registers in BinaryRRF instructions are wrong, and affects the copysign instruction (CPSDR). This results in the wrong magnitude and sign being set.

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zhanjunl updated this revision to Diff 57407.EditedMay 16 2016, 3:21 PM
zhanjunl retitled this revision from to [SystemZ] Fix register ordering for BinaryRRF instructions.
zhanjunl updated this object.
zhanjunl added reviewers: uweigand, kbarton.
zhanjunl added a subscriber: llvm-commits.

A simple testcase is:

#include <stdio.h>
#include <cmath>

double cpsdr(double a, double b) {
  return copysign(a,b);

double a = 1.0;
double b = -2.0;

int main () {
  printf("ret is %lf\n", cpsdr(a, b));
  return 0;

The expected result is -1.0, but the return of clang is 2.0.

uweigand accepted this revision.May 17 2016, 5:11 AM
uweigand edited edge metadata.

LGTM, thanks!

This revision is now accepted and ready to land.May 17 2016, 5:11 AM
This revision was automatically updated to reflect the committed changes.